layout: Implement ordered lists, CSS counters, and `quotes` per CSS 2.1

§ 12.3-12.5.

Only simple alphabetic and numeric counter styles are supported. (This
is most of them though.)

Although this PR adds a sequential pass to layout, I verified that on
pages that contain a reasonable number of ordered lists (Reddit
`/r/rust`), the time spent in generated content resolution is dwarfed by
the time spent in the parallelizable parts of layout. So I don't expect
this to negatively affect our parallelism expect perhaps in pathological
cases.

39 files changed, 1700 insertions, 533 deletions

diff --git a/components/layout/block.rs b/components/layout/block.rs
index 456ee73d09b..77c60b25b3d 100644
--- a/components/layout/block.rs
+++ b/components/layout/block.rs
@@ -27,7 +27,6 @@
 
 #![deny(unsafe_blocks)]
 
-use construct::FlowConstructor;
 use context::LayoutContext;
 use css::node_style::StyledNode;
 use display_list_builder::{BlockFlowDisplayListBuilding, FragmentDisplayListBuilding};
@@ -50,12 +49,8 @@ use wrapper::ThreadSafeLayoutNode;
 
 use geom::{Point2D, Rect, Size2D};
 use gfx::display_list::{ClippingRegion, DisplayList};
-use rustc_serialize::{Encoder, Encodable};
 use msg::compositor_msg::LayerId;
-use msg::constellation_msg::ConstellationChan;
-use util::geometry::{Au, MAX_AU};
-use util::logical_geometry::{LogicalPoint, LogicalRect, LogicalSize, WritingMode};
-use util::opts;
+use rustc_serialize::{Encoder, Encodable};
 use std::cmp::{max, min};
 use std::fmt;
 use style::computed_values::{overflow_x, overflow_y, position, box_sizing, display, float};
@@ -63,6 +58,9 @@ use style::properties::ComputedValues;
 use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto};
 use style::values::computed::{LengthOrPercentageOrNone};
 use std::sync::Arc;
+use util::geometry::{Au, MAX_AU};
+use util::logical_geometry::{LogicalPoint, LogicalRect, LogicalSize, WritingMode};
+use util::opts;
 
 /// Information specific to floated blocks.
 #[derive(Clone, RustcEncodable)]
@@ -570,20 +568,6 @@ impl Encodable for BlockFlowFlags {
 }
 
 impl BlockFlow {
-    pub fn from_node(constructor: &mut FlowConstructor, node: &ThreadSafeLayoutNode) -> BlockFlow {
-        let writing_mode = node.style().writing_mode;
-        BlockFlow {
-            base: BaseFlow::new(Some((*node).clone()), writing_mode, ForceNonfloatedFlag::ForceNonfloated),
-            fragment: Fragment::new(constructor, node),
-            static_b_offset: Au::new(0),
-            inline_size_of_preceding_left_floats: Au(0),
-            inline_size_of_preceding_right_floats: Au(0),
-            hypothetical_position: LogicalPoint::new(writing_mode, Au(0), Au(0)),
-            float: None,
-            flags: BlockFlowFlags::empty(),
-        }
-    }
-
     pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode, fragment: Fragment) -> BlockFlow {
         let writing_mode = node.style().writing_mode;
         BlockFlow {
@@ -598,23 +582,6 @@ impl BlockFlow {
         }
     }
 
-    pub fn float_from_node(constructor: &mut FlowConstructor,
-                           node: &ThreadSafeLayoutNode,
-                           float_kind: FloatKind)
-                           -> BlockFlow {
-        let writing_mode = node.style().writing_mode;
-        BlockFlow {
-            base: BaseFlow::new(Some((*node).clone()), writing_mode, ForceNonfloatedFlag::FloatIfNecessary),
-            fragment: Fragment::new(constructor, node),
-            static_b_offset: Au::new(0),
-            inline_size_of_preceding_left_floats: Au(0),
-            inline_size_of_preceding_right_floats: Au(0),
-            hypothetical_position: LogicalPoint::new(writing_mode, Au(0), Au(0)),
-            float: Some(box FloatedBlockInfo::new(float_kind)),
-            flags: BlockFlowFlags::empty(),
-        }
-    }
-
     pub fn float_from_node_and_fragment(node: &ThreadSafeLayoutNode,
                                         fragment: Fragment,
                                         float_kind: FloatKind)
@@ -1950,8 +1917,8 @@ impl Flow for BlockFlow {
                               .translate(stacking_context_position));
     }
 
-    fn remove_compositor_layers(&self, constellation_chan: ConstellationChan) {
-        self.fragment.remove_compositor_layers(constellation_chan);
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        (*mutator)(&mut self.fragment)
     }
 }
 
diff --git a/components/layout/construct.rs b/components/layout/construct.rs
index b8dd5a8415e..b29b6507c2d 100644
--- a/components/layout/construct.rs
+++ b/components/layout/construct.rs
@@ -16,23 +16,23 @@
 use block::BlockFlow;
 use context::LayoutContext;
 use css::node_style::StyledNode;
+use data::{HAS_NEWLY_CONSTRUCTED_FLOW, LayoutDataAccess, LayoutDataWrapper};
 use floats::FloatKind;
 use flow::{Descendants, AbsDescendants};
 use flow::{Flow, ImmutableFlowUtils, MutableOwnedFlowUtils};
 use flow::{IS_ABSOLUTELY_POSITIONED};
 use flow;
 use flow_ref::FlowRef;
+use fragment::{Fragment, GeneratedContentInfo, IframeFragmentInfo};
 use fragment::CanvasFragmentInfo;
 use fragment::ImageFragmentInfo;
 use fragment::InlineAbsoluteHypotheticalFragmentInfo;
 use fragment::TableColumnFragmentInfo;
 use fragment::UnscannedTextFragmentInfo;
-use fragment::{Fragment, IframeFragmentInfo};
 use fragment::{InlineBlockFragmentInfo, SpecificFragmentInfo};
 use incremental::{RECONSTRUCT_FLOW, RestyleDamage};
 use inline::InlineFlow;
-use data::{HAS_NEWLY_CONSTRUCTED_FLOW, LayoutDataAccess, LayoutDataWrapper};
-use list_item::{self, ListItemFlow};
+use list_item::{ListItemFlow, ListStyleTypeContent};
 use opaque_node::OpaqueNodeMethods;
 use parallel;
 use table::TableFlow;
@@ -55,9 +55,10 @@ use std::borrow::ToOwned;
 use std::collections::DList;
 use std::mem;
 use std::sync::atomic::Ordering;
+use style::computed_values::content::ContentItem;
 use style::computed_values::{caption_side, display, empty_cells, float, list_style_position};
 use style::computed_values::{position};
-use style::properties::{ComputedValues, make_inline};
+use style::properties::{self, ComputedValues};
 use std::sync::Arc;
 use url::Url;
 
@@ -265,41 +266,51 @@ impl<'a> FlowConstructor<'a> {
         }
     }
 
-    /// Builds specific `Fragment` info for the given node.
-    ///
-    /// This does *not* construct the text for generated content (but, for generated content with
-    /// `display: block`, it does construct the generic fragment corresponding to the block).
-    /// Construction of the text fragment is done specially by `build_flow_using_children()` and
-    /// `build_fragments_for_replaced_inline_content()`.
-    pub fn build_specific_fragment_info_for_node(&mut self, node: &ThreadSafeLayoutNode)
-                                                 -> SpecificFragmentInfo {
-        match node.type_id() {
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLIFrameElement))) => {
+    /// Builds the fragment for the given block or subclass thereof.
+    fn build_fragment_for_block(&mut self, node: &ThreadSafeLayoutNode) -> Fragment {
+        let specific_fragment_info = match node.type_id() {
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLIFrameElement))) => {
                 SpecificFragmentInfo::Iframe(box IframeFragmentInfo::new(node))
             }
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLImageElement))) => {
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLImageElement))) => {
                 self.build_fragment_info_for_image(node, node.image_url())
             }
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLObjectElement))) => {
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLObjectElement))) => {
                 let data = node.get_object_data();
                 self.build_fragment_info_for_image(node, data)
             }
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTableElement))) => SpecificFragmentInfo::TableWrapper,
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTableColElement))) => {
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTableElement))) => {
+                SpecificFragmentInfo::TableWrapper
+            }
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTableColElement))) => {
                 SpecificFragmentInfo::TableColumn(TableColumnFragmentInfo::new(node))
             }
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTableCellElement(_)))) => SpecificFragmentInfo::TableCell,
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTableRowElement))) |
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTableSectionElement))) => SpecificFragmentInfo::TableRow,
-            Some(NodeTypeId::Text) => SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::new(node)),
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLCanvasElement))) => {
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTableCellElement(_)))) => {
+                SpecificFragmentInfo::TableCell
+            }
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTableRowElement))) |
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTableSectionElement))) => {
+                SpecificFragmentInfo::TableRow
+            }
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLCanvasElement))) => {
                 SpecificFragmentInfo::Canvas(box CanvasFragmentInfo::new(node))
             }
             _ => {
                 // This includes pseudo-elements.
                 SpecificFragmentInfo::Generic
             }
-        }
+        };
+
+        Fragment::new(node, specific_fragment_info)
     }
 
     /// Creates an inline flow from a set of inline fragments, then adds it as a child of the given
@@ -339,7 +350,9 @@ impl<'a> FlowConstructor<'a> {
         let mut inline_block_flows = vec!();
         for f in fragments.iter() {
             match f.specific {
-                SpecificFragmentInfo::InlineBlock(ref info) => inline_block_flows.push(info.flow_ref.clone()),
+                SpecificFragmentInfo::InlineBlock(ref info) => {
+                    inline_block_flows.push(info.flow_ref.clone())
+                }
                 SpecificFragmentInfo::InlineAbsoluteHypothetical(ref info) => {
                     inline_block_flows.push(info.flow_ref.clone())
                 }
@@ -473,8 +486,8 @@ impl<'a> FlowConstructor<'a> {
                                                                           whitespace_damage)) => {
                 // Add whitespace results. They will be stripped out later on when
                 // between block elements, and retained when between inline elements.
-                let fragment_info =
-                    SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::from_text(" ".to_owned()));
+                let fragment_info = SpecificFragmentInfo::UnscannedText(
+                    UnscannedTextFragmentInfo::from_text(" ".to_owned()));
                 let fragment = Fragment::from_opaque_node_and_style(whitespace_node,
                                                                     whitespace_style,
                                                                     whitespace_damage,
@@ -488,25 +501,20 @@ impl<'a> FlowConstructor<'a> {
         }
     }
 
-    /// Constructs a block flow, beginning with the given `initial_fragment` if present and then
+    /// Constructs a block flow, beginning with the given `initial_fragments` if present and then
     /// appending the construction results of children to the child list of the block flow. {ib}
     /// splits and absolutely-positioned descendants are handled correctly.
-    fn build_flow_for_block_starting_with_fragment(&mut self,
-                                                   mut flow: FlowRef,
-                                                   node: &ThreadSafeLayoutNode,
-                                                   initial_fragment: Option<Fragment>)
-                                                   -> ConstructionResult {
+    fn build_flow_for_block_starting_with_fragments(&mut self,
+                                                    mut flow: FlowRef,
+                                                    node: &ThreadSafeLayoutNode,
+                                                    mut initial_fragments: DList<Fragment>)
+                                                    -> ConstructionResult {
         // Gather up fragments for the inline flows we might need to create.
         let mut inline_fragment_accumulator = InlineFragmentsAccumulator::new();
         let mut consecutive_siblings = vec!();
 
-        let mut first_fragment = match initial_fragment {
-            None => true,
-            Some(initial_fragment) => {
-                inline_fragment_accumulator.fragments.push_back(initial_fragment);
-                false
-            }
-        };
+        inline_fragment_accumulator.fragments.append(&mut initial_fragments);
+        let mut first_fragment = inline_fragment_accumulator.fragments.is_empty();
 
         // List of absolute descendants, in tree order.
         let mut abs_descendants = Descendants::new();
@@ -558,7 +566,7 @@ impl<'a> FlowConstructor<'a> {
 
     /// Constructs a flow for the given block node and its children. This method creates an
     /// initial fragment as appropriate and then dispatches to
-    /// `build_flow_for_block_starting_with_fragment`. Currently the following kinds of flows get
+    /// `build_flow_for_block_starting_with_fragments`. Currently the following kinds of flows get
     /// initial content:
     ///
     /// * Generated content gets the initial content specified by the `content` attribute of the
@@ -569,32 +577,60 @@ impl<'a> FlowConstructor<'a> {
     /// `<textarea>`.
     fn build_flow_for_block(&mut self, flow: FlowRef, node: &ThreadSafeLayoutNode)
                             -> ConstructionResult {
-        let initial_fragment = if node.get_pseudo_element_type() != PseudoElementType::Normal ||
-           node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLInputElement))) ||
-           node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement))) {
+        let mut initial_fragments = DList::new();
+        if node.get_pseudo_element_type() != PseudoElementType::Normal ||
+           node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                       HTMLElementTypeId::HTMLInputElement))) ||
+           node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                       HTMLElementTypeId::HTMLTextAreaElement))) {
             // A TextArea's text contents are displayed through the input text
             // box, so don't construct them.
-            if node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement))) {
+            if node.type_id() == Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLTextAreaElement))) {
                 for kid in node.children() {
-                    self.set_flow_construction_result(&kid, ConstructionResult::None)
+                    kid.set_flow_construction_result(ConstructionResult::None)
                 }
             }
-            Some(Fragment::new_from_specific_info(
-                    node,
-                    SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::new(node))))
-        } else {
-            None
-        };
 
-        self.build_flow_for_block_starting_with_fragment(flow, node, initial_fragment)
+            self.create_fragments_for_node_text_content(&mut initial_fragments, node, node.style());
+        }
+
+        self.build_flow_for_block_starting_with_fragments(flow, node, initial_fragments)
+    }
+
+    /// Pushes fragments appropriate for the content of the given node onto the given list.
+    fn create_fragments_for_node_text_content(&self,
+                                              fragments: &mut DList<Fragment>,
+                                              node: &ThreadSafeLayoutNode,
+                                              style: &Arc<ComputedValues>) {
+        for content_item in node.text_content().into_iter() {
+            let specific = match content_item {
+                ContentItem::String(string) => {
+                    let info = UnscannedTextFragmentInfo::from_text(string);
+                    SpecificFragmentInfo::UnscannedText(info)
+                }
+                content_item => {
+                    let content_item = box GeneratedContentInfo::ContentItem(content_item);
+                    SpecificFragmentInfo::GeneratedContent(content_item)
+                }
+            };
+
+            let opaque_node = OpaqueNodeMethods::from_thread_safe_layout_node(node);
+            fragments.push_back(Fragment::from_opaque_node_and_style(opaque_node,
+                                                                     style.clone(),
+                                                                     node.restyle_damage(),
+                                                                     specific))
+        }
     }
 
+
     /// Builds a flow for a node with `display: block`. This yields a `BlockFlow` with possibly
     /// other `BlockFlow`s or `InlineFlow`s underneath it, depending on whether {ib} splits needed
     /// to happen.
     fn build_flow_for_nonfloated_block(&mut self, node: &ThreadSafeLayoutNode)
                                        -> ConstructionResult {
-        let flow = box BlockFlow::from_node(self, node) as Box<Flow>;
+        let flow = box BlockFlow::from_node_and_fragment(node, self.build_fragment_for_block(node))
+            as Box<Flow>;
         self.build_flow_for_block(FlowRef::new(flow), node)
     }
 
@@ -602,7 +638,9 @@ impl<'a> FlowConstructor<'a> {
     /// a `BlockFlow` underneath it.
     fn build_flow_for_floated_block(&mut self, node: &ThreadSafeLayoutNode, float_kind: FloatKind)
                                     -> ConstructionResult {
-        let flow = box BlockFlow::float_from_node(self, node, float_kind) as Box<Flow>;
+        let fragment = self.build_fragment_for_block(node);
+        let flow = box BlockFlow::float_from_node_and_fragment(node, fragment, float_kind) as
+            Box<Flow>;
         self.build_flow_for_block(FlowRef::new(flow), node)
     }
 
@@ -670,8 +708,8 @@ impl<'a> FlowConstructor<'a> {
                         whitespace_style,
                         whitespace_damage)) => {
                     // Instantiate the whitespace fragment.
-                    let fragment_info = SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::from_text(
-                            " ".to_owned()));
+                    let fragment_info = SpecificFragmentInfo::UnscannedText(
+                        UnscannedTextFragmentInfo::from_text(" ".to_owned()));
                     let fragment = Fragment::from_opaque_node_and_style(whitespace_node,
                                                                         whitespace_style,
                                                                         whitespace_damage,
@@ -706,7 +744,7 @@ impl<'a> FlowConstructor<'a> {
     fn build_fragments_for_replaced_inline_content(&mut self, node: &ThreadSafeLayoutNode)
                                                    -> ConstructionResult {
         for kid in node.children() {
-            self.set_flow_construction_result(&kid, ConstructionResult::None)
+            kid.set_flow_construction_result(ConstructionResult::None)
         }
 
         // If this node is ignorable whitespace, bail out now.
@@ -725,30 +763,22 @@ impl<'a> FlowConstructor<'a> {
         // `baz` had better not be absolutely positioned!
         let mut style = (*node.style()).clone();
         if style.get_box().display != display::T::inline {
-            style = Arc::new(make_inline(&*style))
+            style = Arc::new(properties::make_inline(&*style))
         }
 
         // If this is generated content, then we need to initialize the accumulator with the
         // fragment corresponding to that content. Otherwise, just initialize with the ordinary
         // fragment that needs to be generated for this inline node.
-        let fragment = if node.get_pseudo_element_type() != PseudoElementType::Normal {
-            let fragment_info =
-                SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::new(node));
-            Fragment::from_opaque_node_and_style(
-                OpaqueNodeMethods::from_thread_safe_layout_node(node),
-                style,
-                node.restyle_damage(),
-                fragment_info)
-        } else {
-            Fragment::from_opaque_node_and_style(
-                OpaqueNodeMethods::from_thread_safe_layout_node(node),
-                style,
-                node.restyle_damage(),
-                self.build_specific_fragment_info_for_node(node))
-        };
-
         let mut fragments = DList::new();
-        fragments.push_back(fragment);
+        match (node.get_pseudo_element_type(), node.type_id()) {
+            (_, Some(NodeTypeId::Text)) => {
+                self.create_fragments_for_node_text_content(&mut fragments, node, &style)
+            }
+            (PseudoElementType::Normal, _) => {
+                fragments.push_back(self.build_fragment_for_block(node));
+            }
+            (_, _) => self.create_fragments_for_node_text_content(&mut fragments, node, &style),
+        }
 
         let construction_item =
             ConstructionItem::InlineFragments(InlineFragmentsConstructionResult {
@@ -769,7 +799,7 @@ impl<'a> FlowConstructor<'a> {
 
         let fragment_info = SpecificFragmentInfo::InlineBlock(InlineBlockFragmentInfo::new(
                 block_flow));
-        let fragment = Fragment::new_from_specific_info(node, fragment_info);
+        let fragment = Fragment::new(node, fragment_info);
 
         let mut fragment_accumulator = InlineFragmentsAccumulator::from_inline_node(node);
         fragment_accumulator.fragments.push_back(fragment);
@@ -795,7 +825,7 @@ impl<'a> FlowConstructor<'a> {
 
         let fragment_info = SpecificFragmentInfo::InlineAbsoluteHypothetical(
             InlineAbsoluteHypotheticalFragmentInfo::new(block_flow));
-        let fragment = Fragment::new_from_specific_info(node, fragment_info);
+        let fragment = Fragment::new(node, fragment_info);
 
         let mut fragment_accumulator = InlineFragmentsAccumulator::from_inline_node(node);
         fragment_accumulator.fragments.push_back(fragment);
@@ -880,7 +910,7 @@ impl<'a> FlowConstructor<'a> {
     /// possibly other `TableCaptionFlow`s or `TableFlow`s underneath it.
     fn build_flow_for_table_wrapper(&mut self, node: &ThreadSafeLayoutNode, float_value: float::T)
                                     -> ConstructionResult {
-        let fragment = Fragment::new_from_specific_info(node, SpecificFragmentInfo::TableWrapper);
+        let fragment = Fragment::new(node, SpecificFragmentInfo::TableWrapper);
         let wrapper_flow = match float_value {
             float::T::none => box TableWrapperFlow::from_node_and_fragment(node, fragment),
             _ => {
@@ -890,7 +920,7 @@ impl<'a> FlowConstructor<'a> {
         };
         let mut wrapper_flow = FlowRef::new(wrapper_flow as Box<Flow>);
 
-        let table_fragment = Fragment::new_from_specific_info(node, SpecificFragmentInfo::Table);
+        let table_fragment = Fragment::new(node, SpecificFragmentInfo::Table);
         let table_flow = box TableFlow::from_node_and_fragment(node, table_fragment);
         let table_flow = FlowRef::new(table_flow as Box<Flow>);
 
@@ -924,7 +954,8 @@ impl<'a> FlowConstructor<'a> {
         wrapper_flow.finish();
         let is_positioned = wrapper_flow.as_block().is_positioned();
         let is_fixed_positioned = wrapper_flow.as_block().is_fixed();
-        let is_absolutely_positioned = flow::base(&*wrapper_flow).flags.contains(IS_ABSOLUTELY_POSITIONED);
+        let is_absolutely_positioned =
+            flow::base(&*wrapper_flow).flags.contains(IS_ABSOLUTELY_POSITIONED);
         if is_positioned {
             // This is the containing block for all the absolute descendants.
             wrapper_flow.set_absolute_descendants(abs_descendants);
@@ -947,7 +978,8 @@ impl<'a> FlowConstructor<'a> {
     /// Builds a flow for a node with `display: table-caption`. This yields a `TableCaptionFlow`
     /// with possibly other `BlockFlow`s or `InlineFlow`s underneath it.
     fn build_flow_for_table_caption(&mut self, node: &ThreadSafeLayoutNode) -> ConstructionResult {
-        let flow = box TableCaptionFlow::from_node(self, node) as Box<Flow>;
+        let fragment = self.build_fragment_for_block(node);
+        let flow = box TableCaptionFlow::from_node_and_fragment(node, fragment) as Box<Flow>;
         self.build_flow_for_block(FlowRef::new(flow), node)
     }
 
@@ -955,7 +987,7 @@ impl<'a> FlowConstructor<'a> {
     /// with possibly other `TableRowFlow`s underneath it.
     fn build_flow_for_table_rowgroup(&mut self, node: &ThreadSafeLayoutNode)
                                      -> ConstructionResult {
-        let fragment = Fragment::new_from_specific_info(node, SpecificFragmentInfo::TableRow);
+        let fragment = Fragment::new(node, SpecificFragmentInfo::TableRow);
         let flow = box TableRowGroupFlow::from_node_and_fragment(node, fragment);
         let flow = flow as Box<Flow>;
         self.build_flow_for_block(FlowRef::new(flow), node)
@@ -964,7 +996,7 @@ impl<'a> FlowConstructor<'a> {
     /// Builds a flow for a node with `display: table-row`. This yields a `TableRowFlow` with
     /// possibly other `TableCellFlow`s underneath it.
     fn build_flow_for_table_row(&mut self, node: &ThreadSafeLayoutNode) -> ConstructionResult {
-        let fragment = Fragment::new_from_specific_info(node, SpecificFragmentInfo::TableRow);
+        let fragment = Fragment::new(node, SpecificFragmentInfo::TableRow);
         let flow = box TableRowFlow::from_node_and_fragment(node, fragment) as Box<Flow>;
         self.build_flow_for_block(FlowRef::new(flow), node)
     }
@@ -972,7 +1004,7 @@ impl<'a> FlowConstructor<'a> {
     /// Builds a flow for a node with `display: table-cell`. This yields a `TableCellFlow` with
     /// possibly other `BlockFlow`s or `InlineFlow`s underneath it.
     fn build_flow_for_table_cell(&mut self, node: &ThreadSafeLayoutNode) -> ConstructionResult {
-        let fragment = Fragment::new_from_specific_info(node, SpecificFragmentInfo::TableCell);
+        let fragment = Fragment::new(node, SpecificFragmentInfo::TableCell);
 
         // Determine if the table cell should be hidden. Per CSS 2.1 § 17.6.1.1, this will be true
         // if the cell has any in-flow elements (even empty ones!) and has `empty-cells` set to
@@ -1000,19 +1032,18 @@ impl<'a> FlowConstructor<'a> {
         };
         let marker_fragment = match node.style().get_list().list_style_image {
             Some(ref url) => {
-                Some(Fragment::new_from_specific_info(
-                    node,
-                    self.build_fragment_info_for_image(node, Some((*url).clone()))))
+                Some(Fragment::new(node,
+                                   self.build_fragment_info_for_image(node, Some((*url).clone()))))
             }
             None => {
-                match list_item::static_text_for_list_style_type(node.style()
+                match ListStyleTypeContent::from_list_style_type(node.style()
                                                                      .get_list()
                                                                      .list_style_type) {
-                    None => None,
-                    Some(text) => {
-                        let text = text.to_owned();
+                    ListStyleTypeContent::None => None,
+                    ListStyleTypeContent::StaticText(ch) => {
+                        let text = format!("{}\u{a0}", ch);
                         let mut unscanned_marker_fragments = DList::new();
-                        unscanned_marker_fragments.push_back(Fragment::new_from_specific_info(
+                        unscanned_marker_fragments.push_back(Fragment::new(
                             node,
                             SpecificFragmentInfo::UnscannedText(
                                 UnscannedTextFragmentInfo::from_text(text))));
@@ -1022,6 +1053,9 @@ impl<'a> FlowConstructor<'a> {
                         debug_assert!(marker_fragments.len() == 1);
                         marker_fragments.fragments.into_iter().next()
                     }
+                    ListStyleTypeContent::GeneratedContent(info) => {
+                        Some(Fragment::new(node, SpecificFragmentInfo::GeneratedContent(info)))
+                    }
                 }
             }
         };
@@ -1031,28 +1065,29 @@ impl<'a> FlowConstructor<'a> {
         // we adopt Gecko's behavior rather than WebKit's when the marker causes an {ib} split,
         // which has caused some malaise (Bugzilla #36854) but CSS 2.1 § 12.5.1 lets me do it, so
         // there.
-        let flow;
-        let initial_fragment;
-        match node.style().get_list().list_style_position {
+        let mut initial_fragments = DList::new();
+        let main_fragment = self.build_fragment_for_block(node);
+        let flow = match node.style().get_list().list_style_position {
             list_style_position::T::outside => {
-                flow = box ListItemFlow::from_node_marker_and_flotation(self,
-                                                                        node,
-                                                                        marker_fragment,
-                                                                        flotation);
-                initial_fragment = None;
+                box ListItemFlow::from_node_fragments_and_flotation(node,
+                                                                    main_fragment,
+                                                                    marker_fragment,
+                                                                    flotation)
             }
             list_style_position::T::inside => {
-                flow = box ListItemFlow::from_node_marker_and_flotation(self,
-                                                                        node,
-                                                                        None,
-                                                                        flotation);
-                initial_fragment = marker_fragment;
+                if let Some(marker_fragment) = marker_fragment {
+                    initial_fragments.push_back(marker_fragment)
+                }
+                box ListItemFlow::from_node_fragments_and_flotation(node,
+                                                                    main_fragment,
+                                                                    None,
+                                                                    flotation)
             }
-        }
+        };
 
-        self.build_flow_for_block_starting_with_fragment(FlowRef::new(flow as Box<Flow>),
-                                                         node,
-                                                         initial_fragment)
+        self.build_flow_for_block_starting_with_fragments(FlowRef::new(flow as Box<Flow>),
+                                                          node,
+                                                          initial_fragments)
     }
 
     /// Creates a fragment for a node with `display: table-column`.
@@ -1060,13 +1095,12 @@ impl<'a> FlowConstructor<'a> {
                                         -> ConstructionResult {
         // CSS 2.1 § 17.2.1. Treat all child fragments of a `table-column` as `display: none`.
         for kid in node.children() {
-            self.set_flow_construction_result(&kid, ConstructionResult::None)
+            kid.set_flow_construction_result(ConstructionResult::None)
         }
 
         let specific = SpecificFragmentInfo::TableColumn(TableColumnFragmentInfo::new(node));
-        let construction_item = ConstructionItem::TableColumnFragment(
-            Fragment::new_from_specific_info(node, specific)
-        );
+        let construction_item = ConstructionItem::TableColumnFragment(Fragment::new(node,
+                                                                                    specific));
         ConstructionResult::ConstructionItem(construction_item)
     }
 
@@ -1074,9 +1108,9 @@ impl<'a> FlowConstructor<'a> {
     /// This yields a `TableColGroupFlow`.
     fn build_flow_for_table_colgroup(&mut self, node: &ThreadSafeLayoutNode)
                                      -> ConstructionResult {
-        let fragment = Fragment::new_from_specific_info(
-            node,
-            SpecificFragmentInfo::TableColumn(TableColumnFragmentInfo::new(node)));
+        let fragment =
+            Fragment::new(node,
+                          SpecificFragmentInfo::TableColumn(TableColumnFragmentInfo::new(node)));
         let mut col_fragments = vec!();
         for kid in node.children() {
             // CSS 2.1 § 17.2.1. Treat all non-column child fragments of `table-column-group`
@@ -1092,7 +1126,7 @@ impl<'a> FlowConstructor<'a> {
         if col_fragments.is_empty() {
             debug!("add SpecificFragmentInfo::TableColumn for empty colgroup");
             let specific = SpecificFragmentInfo::TableColumn(TableColumnFragmentInfo::new(node));
-            col_fragments.push(Fragment::new_from_specific_info(node, specific));
+            col_fragments.push(Fragment::new(node, specific));
         }
         let flow = box TableColGroupFlow::from_node_and_fragments(node, fragment, col_fragments);
         let mut flow = FlowRef::new(flow as Box<Flow>);
@@ -1188,15 +1222,15 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             // results of children.
             (display::T::none, _, _) => {
                 for child in node.children() {
-                    self.set_flow_construction_result(&child, ConstructionResult::None);
+                    child.set_flow_construction_result(ConstructionResult::None);
                 }
-                self.set_flow_construction_result(node, ConstructionResult::None);
+                node.set_flow_construction_result(ConstructionResult::None);
             }
 
             // Table items contribute table flow construction results.
             (display::T::table, float_value, _) => {
                 let construction_result = self.build_flow_for_table_wrapper(node, float_value);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Absolutely positioned elements will have computed value of
@@ -1207,14 +1241,13 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             // below.
             (display::T::block, _, position::T::absolute) |
             (_, _, position::T::fixed) => {
-                let construction_result = self.build_flow_for_nonfloated_block(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(self.build_flow_for_nonfloated_block(node))
             }
 
             // List items contribute their own special flows.
             (display::T::list_item, float_value, _) => {
-                let construction_result = self.build_flow_for_list_item(node, float_value);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(self.build_flow_for_list_item(node,
+                                                                                float_value))
             }
 
             // Inline items that are absolutely-positioned contribute inline fragment construction
@@ -1222,7 +1255,7 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             (display::T::inline, _, position::T::absolute) => {
                 let construction_result =
                     self.build_fragment_for_absolutely_positioned_inline(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Inline items contribute inline fragment construction results.
@@ -1230,31 +1263,31 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             // FIXME(pcwalton, #3307): This is not sufficient to handle floated generated content.
             (display::T::inline, float::T::none, _) => {
                 let construction_result = self.build_fragments_for_inline(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Inline-block items contribute inline fragment construction results.
             (display::T::inline_block, float::T::none, _) => {
                 let construction_result = self.build_fragment_for_inline_block(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
             (display::T::table_caption, _, _) => {
                 let construction_result = self.build_flow_for_table_caption(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
             (display::T::table_column_group, _, _) => {
                 let construction_result = self.build_flow_for_table_colgroup(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
             (display::T::table_column, _, _) => {
                 let construction_result = self.build_fragments_for_table_column(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
@@ -1262,19 +1295,19 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             (display::T::table_header_group, _, _) |
             (display::T::table_footer_group, _, _) => {
                 let construction_result = self.build_flow_for_table_rowgroup(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
             (display::T::table_row, _, _) => {
                 let construction_result = self.build_flow_for_table_row(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Table items contribute table flow construction results.
             (display::T::table_cell, _, _) => {
                 let construction_result = self.build_flow_for_table_cell(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(construction_result)
             }
 
             // Block flows that are not floated contribute block flow construction results.
@@ -1283,15 +1316,14 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             // properties separately.
 
             (_, float::T::none, _) => {
-                let construction_result = self.build_flow_for_nonfloated_block(node);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(self.build_flow_for_nonfloated_block(node))
             }
 
             // Floated flows contribute float flow construction results.
             (_, float_value, _) => {
                 let float_kind = FloatKind::from_property(float_value);
-                let construction_result = self.build_flow_for_floated_block(node, float_kind);
-                self.set_flow_construction_result(node, construction_result)
+                node.set_flow_construction_result(
+                    self.build_flow_for_floated_block(node, float_kind))
             }
         }
 
@@ -1310,25 +1342,29 @@ trait NodeUtils {
     /// Sets the construction result of a flow.
     fn set_flow_construction_result(self, result: ConstructionResult);
 
-    /// Replaces the flow construction result in a node with `ConstructionResult::None` and returns the
-    /// old value.
+    /// Replaces the flow construction result in a node with `ConstructionResult::None` and returns
+    /// the old value.
     fn swap_out_construction_result(self) -> ConstructionResult;
 }
 
 impl<'ln> NodeUtils for ThreadSafeLayoutNode<'ln> {
     fn is_replaced_content(&self) -> bool {
         match self.type_id() {
+            None |
             Some(NodeTypeId::Text) |
             Some(NodeTypeId::ProcessingInstruction) |
             Some(NodeTypeId::Comment) |
             Some(NodeTypeId::DocumentType) |
             Some(NodeTypeId::DocumentFragment) |
             Some(NodeTypeId::Document) |
-            None |
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLImageElement))) => true,
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLObjectElement))) => self.has_object_data(),
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLIFrameElement))) => true,
-            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLCanvasElement))) => true,
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLImageElement))) |
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLIFrameElement))) |
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLCanvasElement))) => true,
+            Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
+                        HTMLElementTypeId::HTMLObjectElement))) => self.has_object_data(),
             Some(NodeTypeId::Element(_)) => false,
         }
     }
diff --git a/components/layout/display_list_builder.rs b/components/layout/display_list_builder.rs
index b5985a8a937..fe361cd2575 100644
--- a/components/layout/display_list_builder.rs
+++ b/components/layout/display_list_builder.rs
@@ -957,6 +957,7 @@ impl FragmentDisplayListBuilding for Fragment {
                 }
             }
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(..) |
             SpecificFragmentInfo::Iframe(..) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
diff --git a/components/layout/flow.rs b/components/layout/flow.rs
index 6049afa8634..1d737348c54 100644
--- a/components/layout/flow.rs
+++ b/components/layout/flow.rs
@@ -33,9 +33,9 @@ use floats::Floats;
 use flow_list::{FlowList, FlowListIterator, MutFlowListIterator};
 use flow_ref::FlowRef;
 use fragment::{Fragment, FragmentBorderBoxIterator, SpecificFragmentInfo};
-use incremental::{RECONSTRUCT_FLOW, REFLOW, REFLOW_OUT_OF_FLOW, RestyleDamage};
+use incremental::{self, RECONSTRUCT_FLOW, REFLOW, REFLOW_OUT_OF_FLOW, RestyleDamage};
 use inline::InlineFlow;
-use model::{CollapsibleMargins, IntrinsicISizes};
+use model::{CollapsibleMargins, IntrinsicISizes, MarginCollapseInfo};
 use parallel::FlowParallelInfo;
 use table::{ColumnComputedInlineSize, ColumnIntrinsicInlineSize, TableFlow};
 use table_caption::TableCaptionFlow;
@@ -236,6 +236,15 @@ pub trait Flow: fmt::Debug + Sync {
                                              iterator: &mut FragmentBorderBoxIterator,
                                              stacking_context_position: &Point2D<Au>);
 
+    /// Mutably iterates through fragments in this flow.
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment));
+
+    fn compute_collapsible_block_start_margin(&mut self,
+                                              _layout_context: &mut LayoutContext,
+                                              _margin_collapse_info: &mut MarginCollapseInfo) {
+        // The default implementation is a no-op.
+    }
+
     /// Marks this flow as the root flow. The default implementation is a no-op.
     fn mark_as_root(&mut self) {}
 
@@ -478,51 +487,67 @@ pub trait PostorderFlowTraversal {
     }
 }
 
+/// An in-order (sequential only) traversal.
+pub trait InorderFlowTraversal {
+    /// The operation to perform. Returns the level of the tree we're at.
+    fn process(&mut self, flow: &mut Flow, level: u32);
+
+    /// Returns true if this node should be processed and false if neither this node nor its
+    /// descendants should be processed.
+    fn should_process(&mut self, flow: &mut Flow) -> bool;
+}
+
 bitflags! {
     #[doc = "Flags used in flows."]
-    flags FlowFlags: u16 {
+    flags FlowFlags: u32 {
         // floated descendants flags
         #[doc = "Whether this flow has descendants that float left in the same block formatting"]
         #[doc = "context."]
-        const HAS_LEFT_FLOATED_DESCENDANTS = 0b0000_0000_0000_0001,
+        const HAS_LEFT_FLOATED_DESCENDANTS = 0b0000_0000_0000_0000_0001,
         #[doc = "Whether this flow has descendants that float right in the same block formatting"]
         #[doc = "context."]
-        const HAS_RIGHT_FLOATED_DESCENDANTS = 0b0000_0000_0000_0010,
+        const HAS_RIGHT_FLOATED_DESCENDANTS = 0b0000_0000_0000_0000_0010,
         #[doc = "Whether this flow is impacted by floats to the left in the same block formatting"]
         #[doc = "context (i.e. its height depends on some prior flows with `float: left`)."]
-        const IMPACTED_BY_LEFT_FLOATS = 0b0000_0000_0000_0100,
+        const IMPACTED_BY_LEFT_FLOATS = 0b0000_0000_0000_0000_0100,
         #[doc = "Whether this flow is impacted by floats to the right in the same block"]
         #[doc = "formatting context (i.e. its height depends on some prior flows with `float:"]
         #[doc = "right`)."]
-        const IMPACTED_BY_RIGHT_FLOATS = 0b0000_0000_0000_1000,
+        const IMPACTED_BY_RIGHT_FLOATS = 0b0000_0000_0000_0000_1000,
 
         // text align flags
         #[doc = "Whether this flow contains a flow that has its own layer within the same absolute"]
         #[doc = "containing block."]
-        const LAYERS_NEEDED_FOR_DESCENDANTS = 0b0000_0000_0001_0000,
+        const LAYERS_NEEDED_FOR_DESCENDANTS = 0b0000_0000_0000_0001_0000,
         #[doc = "Whether this flow must have its own layer. Even if this flag is not set, it might"]
         #[doc = "get its own layer if it's deemed to be likely to overlap flows with their own"]
         #[doc = "layer."]
-        const NEEDS_LAYER = 0b0000_0000_0010_0000,
+        const NEEDS_LAYER = 0b0000_0000_0000_0010_0000,
         #[doc = "Whether this flow is absolutely positioned. This is checked all over layout, so a"]
         #[doc = "virtual call is too expensive."]
-        const IS_ABSOLUTELY_POSITIONED = 0b0000_0000_0100_0000,
+        const IS_ABSOLUTELY_POSITIONED = 0b0000_0000_0000_0100_0000,
         #[doc = "Whether this flow clears to the left. This is checked all over layout, so a"]
         #[doc = "virtual call is too expensive."]
-        const CLEARS_LEFT = 0b0000_0000_1000_0000,
+        const CLEARS_LEFT = 0b0000_0000_0000_1000_0000,
         #[doc = "Whether this flow clears to the right. This is checked all over layout, so a"]
         #[doc = "virtual call is too expensive."]
-        const CLEARS_RIGHT = 0b0000_0001_0000_0000,
+        const CLEARS_RIGHT = 0b0000_0000_0001_0000_0000,
         #[doc = "Whether this flow is left-floated. This is checked all over layout, so a"]
         #[doc = "virtual call is too expensive."]
-        const FLOATS_LEFT = 0b0000_0010_0000_0000,
+        const FLOATS_LEFT = 0b0000_0000_0010_0000_0000,
         #[doc = "Whether this flow is right-floated. This is checked all over layout, so a"]
         #[doc = "virtual call is too expensive."]
-        const FLOATS_RIGHT = 0b0000_0100_0000_0000,
+        const FLOATS_RIGHT = 0b0000_0000_0100_0000_0000,
         #[doc = "Text alignment. \
 
                  NB: If you update this, update `TEXT_ALIGN_SHIFT` below."]
-        const TEXT_ALIGN = 0b0111_1000_0000_0000,
+        const TEXT_ALIGN = 0b0000_0111_1000_0000_0000,
+        #[doc = "Whether this flow has a fragment with `counter-reset` or `counter-increment` \
+                 styles."]
+        const AFFECTS_COUNTERS = 0b0000_1000_0000_0000_0000,
+        #[doc = "Whether this flow's descendants have fragments that affect `counter-reset` or \
+                 `counter-increment` styles."]
+        const HAS_COUNTER_AFFECTING_CHILDREN = 0b0001_0000_0000_0000_0000
     }
 }
 
@@ -548,13 +573,13 @@ impl FlowFlags {
 
     #[inline]
     pub fn text_align(self) -> text_align::T {
-        FromPrimitive::from_u16((self & TEXT_ALIGN).bits() >> TEXT_ALIGN_SHIFT).unwrap()
+        FromPrimitive::from_u32((self & TEXT_ALIGN).bits() >> TEXT_ALIGN_SHIFT).unwrap()
     }
 
     #[inline]
     pub fn set_text_align(&mut self, value: text_align::T) {
         *self = (*self & !TEXT_ALIGN) |
-            FlowFlags::from_bits((value as u16) << TEXT_ALIGN_SHIFT).unwrap();
+            FlowFlags::from_bits((value as u32) << TEXT_ALIGN_SHIFT).unwrap();
     }
 
     #[inline]
@@ -885,39 +910,41 @@ impl BaseFlow {
                force_nonfloated: ForceNonfloatedFlag)
                -> BaseFlow {
         let mut flags = FlowFlags::empty();
-        match node {
-            None => {}
-            Some(node) => {
-                let node_style = node.style();
-                match node_style.get_box().position {
-                    position::T::absolute | position::T::fixed => {
-                        flags.insert(IS_ABSOLUTELY_POSITIONED)
-                    }
-                    _ => {}
+        if let Some(node) = node {
+            let node_style = node.style();
+            match node_style.get_box().position {
+                position::T::absolute | position::T::fixed => {
+                    flags.insert(IS_ABSOLUTELY_POSITIONED)
                 }
+                _ => {}
+            }
 
-                if force_nonfloated == ForceNonfloatedFlag::FloatIfNecessary {
-                    match node_style.get_box().float {
-                        float::T::none => {}
-                        float::T::left => flags.insert(FLOATS_LEFT),
-                        float::T::right => flags.insert(FLOATS_RIGHT),
-                    }
+            if force_nonfloated == ForceNonfloatedFlag::FloatIfNecessary {
+                match node_style.get_box().float {
+                    float::T::none => {}
+                    float::T::left => flags.insert(FLOATS_LEFT),
+                    float::T::right => flags.insert(FLOATS_RIGHT),
                 }
+            }
 
-                match node_style.get_box().clear {
-                    clear::T::none => {}
-                    clear::T::left => flags.insert(CLEARS_LEFT),
-                    clear::T::right => flags.insert(CLEARS_RIGHT),
-                    clear::T::both => {
-                        flags.insert(CLEARS_LEFT);
-                        flags.insert(CLEARS_RIGHT);
-                    }
+            match node_style.get_box().clear {
+                clear::T::none => {}
+                clear::T::left => flags.insert(CLEARS_LEFT),
+                clear::T::right => flags.insert(CLEARS_RIGHT),
+                clear::T::both => {
+                    flags.insert(CLEARS_LEFT);
+                    flags.insert(CLEARS_RIGHT);
                 }
             }
+
+            if !node_style.get_counters().counter_reset.0.is_empty() ||
+                    !node_style.get_counters().counter_increment.0.is_empty() {
+                flags.insert(AFFECTS_COUNTERS)
+            }
         }
 
         // New flows start out as fully damaged.
-        let mut damage = RestyleDamage::all();
+        let mut damage = incremental::rebuild_and_reflow();
         damage.remove(RECONSTRUCT_FLOW);
 
         BaseFlow {
@@ -992,10 +1019,12 @@ impl BaseFlow {
 }
 
 impl<'a> ImmutableFlowUtils for &'a (Flow + 'a) {
-    /// Returns true if this flow is a block flow.
+    /// Returns true if this flow is a block flow or subclass thereof.
     fn is_block_like(self) -> bool {
         match self.class() {
-            FlowClass::Block => true,
+            FlowClass::Block | FlowClass::ListItem | FlowClass::Table | FlowClass::TableRowGroup |
+            FlowClass::TableRow | FlowClass::TableCaption | FlowClass::TableCell |
+            FlowClass::TableWrapper => true,
             _ => false,
         }
     }
diff --git a/components/layout/fragment.rs b/components/layout/fragment.rs
index 4faa266217c..3b8dff61e63 100644
--- a/components/layout/fragment.rs
+++ b/components/layout/fragment.rs
@@ -8,13 +8,12 @@
 
 use canvas::canvas_paint_task::CanvasMsg;
 use css::node_style::StyledNode;
-use construct::FlowConstructor;
 use context::LayoutContext;
 use floats::ClearType;
 use flow;
 use flow::Flow;
 use flow_ref::FlowRef;
-use incremental::RestyleDamage;
+use incremental::{self, RestyleDamage};
 use inline::{InlineFragmentContext, InlineMetrics};
 use layout_debug;
 use model::{IntrinsicISizes, IntrinsicISizesContribution, MaybeAuto, specified};
@@ -44,15 +43,17 @@ use std::collections::DList;
 use std::fmt;
 use std::num::ToPrimitive;
 use std::str::FromStr;
-use std::sync::{Arc, Mutex};
 use std::sync::mpsc::Sender;
+use std::sync::{Arc, Mutex};
 use string_cache::Atom;
-use style::properties::{ComputedValues, cascade_anonymous, make_border};
-use style::node::{TElement, TNode};
-use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto, LengthOrPercentageOrNone};
+use style::computed_values::content::ContentItem;
 use style::computed_values::{clear, mix_blend_mode, overflow_wrap};
 use style::computed_values::{position, text_align, text_decoration, vertical_align, white_space};
 use style::computed_values::{word_break};
+use style::node::{TElement, TNode};
+use style::properties::{ComputedValues, cascade_anonymous, make_border};
+use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto};
+use style::values::computed::{LengthOrPercentageOrNone};
 use text::TextRunScanner;
 use url::Url;
 
@@ -136,6 +137,11 @@ impl Encodable for Fragment {
 #[derive(Clone)]
 pub enum SpecificFragmentInfo {
     Generic,
+
+    /// A piece of generated content that cannot be resolved into `ScannedText` until the generated
+    /// content resolution phase (e.g. an ordered list item marker).
+    GeneratedContent(Box<GeneratedContentInfo>),
+
     Iframe(Box<IframeFragmentInfo>),
     Image(Box<ImageFragmentInfo>),
     Canvas(Box<CanvasFragmentInfo>),
@@ -158,17 +164,18 @@ impl SpecificFragmentInfo {
     fn restyle_damage(&self) -> RestyleDamage {
         let flow =
             match *self {
-                SpecificFragmentInfo::Iframe(_)
-                | SpecificFragmentInfo::Image(_)
-                | SpecificFragmentInfo::ScannedText(_)
-                | SpecificFragmentInfo::Table
-                | SpecificFragmentInfo::TableCell
-                | SpecificFragmentInfo::TableColumn(_)
-                | SpecificFragmentInfo::TableRow
-                | SpecificFragmentInfo::TableWrapper
-                | SpecificFragmentInfo::UnscannedText(_)
-                | SpecificFragmentInfo::Canvas(_)
-                | SpecificFragmentInfo::Generic => return RestyleDamage::empty(),
+                SpecificFragmentInfo::Canvas(_) |
+                SpecificFragmentInfo::GeneratedContent(_) |
+                SpecificFragmentInfo::Iframe(_) |
+                SpecificFragmentInfo::Image(_) |
+                SpecificFragmentInfo::ScannedText(_) |
+                SpecificFragmentInfo::Table |
+                SpecificFragmentInfo::TableCell |
+                SpecificFragmentInfo::TableColumn(_) |
+                SpecificFragmentInfo::TableRow |
+                SpecificFragmentInfo::TableWrapper |
+                SpecificFragmentInfo::UnscannedText(_) |
+                SpecificFragmentInfo::Generic => return RestyleDamage::empty(),
                 SpecificFragmentInfo::InlineAbsoluteHypothetical(ref info) => &info.flow_ref,
                 SpecificFragmentInfo::InlineBlock(ref info) => &info.flow_ref,
             };
@@ -180,9 +187,12 @@ impl SpecificFragmentInfo {
         match *self {
             SpecificFragmentInfo::Canvas(_) => "SpecificFragmentInfo::Canvas",
             SpecificFragmentInfo::Generic => "SpecificFragmentInfo::Generic",
+            SpecificFragmentInfo::GeneratedContent(_) => "SpecificFragmentInfo::GeneratedContent",
             SpecificFragmentInfo::Iframe(_) => "SpecificFragmentInfo::Iframe",
             SpecificFragmentInfo::Image(_) => "SpecificFragmentInfo::Image",
-            SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => "SpecificFragmentInfo::InlineAbsoluteHypothetical",
+            SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => {
+                "SpecificFragmentInfo::InlineAbsoluteHypothetical"
+            }
             SpecificFragmentInfo::InlineBlock(_) => "SpecificFragmentInfo::InlineBlock",
             SpecificFragmentInfo::ScannedText(_) => "SpecificFragmentInfo::ScannedText",
             SpecificFragmentInfo::Table => "SpecificFragmentInfo::Table",
@@ -196,8 +206,11 @@ impl SpecificFragmentInfo {
 }
 
 /// Clamp a value obtained from style_length, based on min / max lengths.
-fn clamp_size(size: Au, min_size: LengthOrPercentage, max_size: LengthOrPercentageOrNone,
-                    container_inline_size: Au) -> Au {
+fn clamp_size(size: Au,
+              min_size: LengthOrPercentage,
+              max_size: LengthOrPercentageOrNone,
+              container_inline_size: Au)
+              -> Au {
     let min_size = model::specified(min_size, container_inline_size);
     let max_size = model::specified_or_none(max_size, container_inline_size);
 
@@ -207,6 +220,13 @@ fn clamp_size(size: Au, min_size: LengthOrPercentage, max_size: LengthOrPercenta
     })
 }
 
+/// Information for generated content.
+#[derive(Clone)]
+pub enum GeneratedContentInfo {
+    ListItem,
+    ContentItem(ContentItem),
+}
+
 /// A hypothetical box (see CSS 2.1 § 10.3.7) for an absolutely-positioned block that was declared
 /// with `display: inline;`.
 ///
@@ -637,14 +657,6 @@ pub struct UnscannedTextFragmentInfo {
 }
 
 impl UnscannedTextFragmentInfo {
-    /// Creates a new instance of `UnscannedTextFragmentInfo` from the given DOM node.
-    pub fn new(node: &ThreadSafeLayoutNode) -> UnscannedTextFragmentInfo {
-        // FIXME(pcwalton): Don't copy text; atomically reference count it instead.
-        UnscannedTextFragmentInfo {
-            text: box node.text(),
-        }
-    }
-
     /// Creates a new instance of `UnscannedTextFragmentInfo` from the given text.
     #[inline]
     pub fn from_text(text: String) -> UnscannedTextFragmentInfo {
@@ -678,34 +690,8 @@ impl TableColumnFragmentInfo {
 }
 
 impl Fragment {
-    /// Constructs a new `Fragment` instance for the given node.
-    ///
-    /// This does *not* construct the text for generated content. See comments in
-    /// `FlowConstructor::build_specific_fragment_info_for_node()` for more details.
-    ///
-    /// Arguments:
-    ///
-    ///   * `constructor`: The flow constructor.
-    ///   * `node`: The node to create a fragment for.
-    pub fn new(constructor: &mut FlowConstructor, node: &ThreadSafeLayoutNode) -> Fragment {
-        let style = node.style().clone();
-        let writing_mode = style.writing_mode;
-        Fragment {
-            node: OpaqueNodeMethods::from_thread_safe_layout_node(node),
-            style: style,
-            restyle_damage: node.restyle_damage(),
-            border_box: LogicalRect::zero(writing_mode),
-            border_padding: LogicalMargin::zero(writing_mode),
-            margin: LogicalMargin::zero(writing_mode),
-            specific: constructor.build_specific_fragment_info_for_node(node),
-            inline_context: None,
-            debug_id: layout_debug::generate_unique_debug_id(),
-        }
-    }
-
-    /// Constructs a new `Fragment` instance from a specific info.
-    pub fn new_from_specific_info(node: &ThreadSafeLayoutNode, specific: SpecificFragmentInfo)
-                                  -> Fragment {
+    /// Constructs a new `Fragment` instance.
+    pub fn new(node: &ThreadSafeLayoutNode, specific: SpecificFragmentInfo) -> Fragment {
         let style = node.style().clone();
         let writing_mode = style.writing_mode;
         Fragment {
@@ -721,24 +707,6 @@ impl Fragment {
         }
     }
 
-    /// Constructs a new `Fragment` instance for an anonymous object.
-    pub fn new_anonymous(constructor: &mut FlowConstructor, node: &ThreadSafeLayoutNode)
-                         -> Fragment {
-        let node_style = cascade_anonymous(&**node.style());
-        let writing_mode = node_style.writing_mode;
-        Fragment {
-            node: OpaqueNodeMethods::from_thread_safe_layout_node(node),
-            style: Arc::new(node_style),
-            restyle_damage: node.restyle_damage(),
-            border_box: LogicalRect::zero(writing_mode),
-            border_padding: LogicalMargin::zero(writing_mode),
-            margin: LogicalMargin::zero(writing_mode),
-            specific: constructor.build_specific_fragment_info_for_node(node),
-            inline_context: None,
-            debug_id: layout_debug::generate_unique_debug_id(),
-        }
-    }
-
     /// Constructs a new `Fragment` instance for an anonymous table object.
     pub fn new_anonymous_from_specific_info(node: &ThreadSafeLayoutNode,
                                             specific: SpecificFragmentInfo)
@@ -837,7 +805,7 @@ impl Fragment {
         Fragment {
             node: self.node,
             style: self.style.clone(),
-            restyle_damage: RestyleDamage::all(),
+            restyle_damage: incremental::rebuild_and_reflow(),
             border_box: new_border_box,
             border_padding: self.border_padding,
             margin: self.margin,
@@ -912,6 +880,7 @@ impl Fragment {
         match self.specific {
             SpecificFragmentInfo::Canvas(_) |
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Image(_) |
             SpecificFragmentInfo::InlineBlock(_) => {
@@ -931,7 +900,9 @@ impl Fragment {
                 INTRINSIC_INLINE_SIZE_INCLUDES_BORDER |
                     INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED
             }
-            SpecificFragmentInfo::ScannedText(_) | SpecificFragmentInfo::TableColumn(_) | SpecificFragmentInfo::UnscannedText(_) |
+            SpecificFragmentInfo::ScannedText(_) |
+            SpecificFragmentInfo::TableColumn(_) |
+            SpecificFragmentInfo::UnscannedText(_) |
             SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => {
                 QuantitiesIncludedInIntrinsicInlineSizes::empty()
             }
@@ -1221,6 +1192,14 @@ impl Fragment {
         }
     }
 
+    /// Returns true if and only if this fragment is a generated content fragment.
+    pub fn is_generated_content(&self) -> bool {
+        match self.specific {
+            SpecificFragmentInfo::GeneratedContent(..) => true,
+            _ => false,
+        }
+    }
+
     /// Returns true if and only if this is a scanned text fragment.
     pub fn is_scanned_text_fragment(&self) -> bool {
         match self.specific {
@@ -1234,6 +1213,7 @@ impl Fragment {
         let mut result = self.style_specified_intrinsic_inline_size();
         match self.specific {
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
@@ -1303,6 +1283,7 @@ impl Fragment {
     pub fn content_inline_size(&self) -> Au {
         match self.specific {
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
@@ -1334,6 +1315,7 @@ impl Fragment {
     pub fn content_block_size(&self, layout_context: &LayoutContext) -> Au {
         match self.specific {
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
@@ -1352,7 +1334,7 @@ impl Fragment {
                 self.calculate_line_height(layout_context)
             }
             SpecificFragmentInfo::TableColumn(_) => {
-                panic!("Table column fragments do not have block_size")
+                panic!("Table column fragments do not have block size")
             }
             SpecificFragmentInfo::UnscannedText(_) => {
                 panic!("Unscanned text fragments should have been scanned by now!")
@@ -1382,6 +1364,7 @@ impl Fragment {
         match self.specific {
             SpecificFragmentInfo::Canvas(_) |
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Image(_) |
             SpecificFragmentInfo::Table |
@@ -1689,22 +1672,23 @@ impl Fragment {
     pub fn assign_replaced_inline_size_if_necessary<'a>(&'a mut self, container_inline_size: Au) {
         match self.specific {
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
             SpecificFragmentInfo::TableRow |
             SpecificFragmentInfo::TableWrapper => return,
             SpecificFragmentInfo::TableColumn(_) => {
-                panic!("Table column fragments do not have inline_size")
+                panic!("Table column fragments do not have inline size")
             }
             SpecificFragmentInfo::UnscannedText(_) => {
                 panic!("Unscanned text fragments should have been scanned by now!")
             }
             SpecificFragmentInfo::Canvas(_) |
             SpecificFragmentInfo::Image(_) |
-            SpecificFragmentInfo::ScannedText(_) |
+            SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::InlineBlock(_) |
             SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
-            SpecificFragmentInfo::Iframe(_) => {}
+            SpecificFragmentInfo::ScannedText(_) => {}
         };
 
         let style = self.style().clone();
@@ -1770,22 +1754,23 @@ impl Fragment {
     pub fn assign_replaced_block_size_if_necessary(&mut self, containing_block_block_size: Au) {
         match self.specific {
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Table |
             SpecificFragmentInfo::TableCell |
             SpecificFragmentInfo::TableRow |
             SpecificFragmentInfo::TableWrapper => return,
             SpecificFragmentInfo::TableColumn(_) => {
-                panic!("Table column fragments do not have block_size")
+                panic!("Table column fragments do not have block size")
             }
             SpecificFragmentInfo::UnscannedText(_) => {
                 panic!("Unscanned text fragments should have been scanned by now!")
             }
             SpecificFragmentInfo::Canvas(_) |
+            SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Image(_) |
-            SpecificFragmentInfo::ScannedText(_) |
             SpecificFragmentInfo::InlineBlock(_) |
             SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
-            SpecificFragmentInfo::Iframe(_) => {}
+            SpecificFragmentInfo::ScannedText(_) => {}
         }
 
         let style = self.style().clone();
@@ -1923,6 +1908,7 @@ impl Fragment {
             SpecificFragmentInfo::TableWrapper => false,
             SpecificFragmentInfo::Canvas(_) |
             SpecificFragmentInfo::Generic |
+            SpecificFragmentInfo::GeneratedContent(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Image(_) |
             SpecificFragmentInfo::ScannedText(_) |
diff --git a/components/layout/generated_content.rs b/components/layout/generated_content.rs
new file mode 100644
index 00000000000..f90e8f79753
--- /dev/null
+++ b/components/layout/generated_content.rs
@@ -0,0 +1,561 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! The generated content assignment phase.
+//!
+//! This phase handles CSS counters, quotes, and ordered lists per CSS § 12.3-12.5. It cannot be
+//! done in parallel and is therefore a sequential pass that runs on as little of the flow tree
+//! as possible.
+
+use context::LayoutContext;
+use flow::{self, AFFECTS_COUNTERS, Flow, HAS_COUNTER_AFFECTING_CHILDREN, ImmutableFlowUtils};
+use flow::{InorderFlowTraversal};
+use fragment::{Fragment, GeneratedContentInfo, SpecificFragmentInfo, UnscannedTextFragmentInfo};
+use incremental::{self, RESOLVE_GENERATED_CONTENT};
+use text::TextRunScanner;
+
+use gfx::display_list::OpaqueNode;
+use std::collections::{DList, HashMap};
+use std::sync::Arc;
+use style::computed_values::content::ContentItem;
+use style::computed_values::{display, list_style_type};
+use style::properties::ComputedValues;
+use util::smallvec::{SmallVec, SmallVec8};
+
+// Decimal styles per CSS-COUNTER-STYLES § 6.1:
+static DECIMAL: [char; 10] = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
+// TODO(pcwalton): `decimal-leading-zero`
+static ARABIC_INDIC: [char; 10] = [ '٠', '١', '٢', '٣', '٤', '٥', '٦', '٧', '٨', '٩' ];
+// TODO(pcwalton): `armenian`, `upper-armenian`, `lower-armenian`
+static BENGALI: [char; 10] = [ '০', '১', '২', '৩', '৪', '৫', '৬', '৭', '৮', '৯' ];
+static CAMBODIAN: [char; 10] = [ '០', '១', '២', '៣', '៤', '៥', '៦', '៧', '៨', '៩' ];
+// TODO(pcwalton): Suffix for CJK decimal.
+static CJK_DECIMAL: [char; 10] = [ '〇', '一', '二', '三', '四', '五', '六', '七', '八', '九' ];
+static DEVANAGARI: [char; 10] = [ '०', '१', '२', '३', '४', '५', '६', '७', '८', '९' ];
+// TODO(pcwalton): `georgian`
+static GUJARATI: [char; 10] = ['૦', '૧', '૨', '૩', '૪', '૫', '૬', '૭', '૮', '૯'];
+static GURMUKHI: [char; 10] = ['੦', '੧', '੨', '੩', '੪', '੫', '੬', '੭', '੮', '੯'];
+// TODO(pcwalton): `hebrew`
+static KANNADA: [char; 10] = ['೦', '೧', '೨', '೩', '೪', '೫', '೬', '೭', '೮', '೯'];
+static LAO: [char; 10] = ['໐', '໑', '໒', '໓', '໔', '໕', '໖', '໗', '໘', '໙'];
+static MALAYALAM: [char; 10] = ['൦', '൧', '൨', '൩', '൪', '൫', '൬', '൭', '൮', '൯'];
+static MONGOLIAN: [char; 10] = ['᠐', '᠑', '᠒', '᠓', '᠔', '᠕', '᠖', '᠗', '᠘', '᠙'];
+static MYANMAR: [char; 10] = ['၀', '၁', '၂', '၃', '၄', '၅', '၆', '၇', '၈', '၉'];
+static ORIYA: [char; 10] = ['୦', '୧', '୨', '୩', '୪', '୫', '୬', '୭', '୮', '୯'];
+static PERSIAN: [char; 10] = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'];
+// TODO(pcwalton): `lower-roman`, `upper-roman`
+static TELUGU: [char; 10] = ['౦', '౧', '౨', '౩', '౪', '౫', '౬', '౭', '౮', '౯'];
+static THAI: [char; 10] = ['๐', '๑', '๒', '๓', '๔', '๕', '๖', '๗', '๘', '๙'];
+static TIBETAN: [char; 10] = ['༠', '༡', '༢', '༣', '༤', '༥', '༦', '༧', '༨', '༩'];
+
+// Alphabetic styles per CSS-COUNTER-STYLES § 6.2:
+static LOWER_ALPHA: [char; 26] = [
+    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
+    't', 'u', 'v', 'w', 'x', 'y', 'z'
+];
+static UPPER_ALPHA: [char; 26] = [
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
+    'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
+];
+static CJK_EARTHLY_BRANCH: [char; 12] = [
+    '子', '丑', '寅', '卯', '辰', '巳', '午', '未', '申', '酉', '戌', '亥'
+];
+static CJK_HEAVENLY_STEM: [char; 10] = [
+    '甲', '乙', '丙', '丁', '戊', '己', '庚', '辛', '壬', '癸'
+];
+static LOWER_GREEK: [char; 24] = [
+    'α', 'β', 'γ', 'δ', 'ε', 'ζ', 'η', 'θ', 'ι', 'κ', 'λ', 'μ', 'ν', 'ξ', 'ο', 'π', 'ρ', 'σ', 'τ',
+    'υ', 'φ', 'χ', 'ψ', 'ω'
+];
+static HIRAGANA: [char; 48] = [
+    'あ', 'い', 'う', 'え', 'お', 'か', 'き', 'く', 'け', 'こ', 'さ', 'し', 'す', 'せ', 'そ',
+    'た', 'ち', 'つ', 'て', 'と', 'な', 'に', 'ぬ', 'ね', 'の', 'は', 'ひ', 'ふ', 'へ', 'ほ',
+    'ま', 'み', 'む', 'め', 'も', 'や', 'ゆ', 'よ', 'ら', 'り', 'る', 'れ', 'ろ',
+    'わ', 'ゐ', 'ゑ', 'を', 'ん'
+];
+static HIRAGANA_IROHA: [char; 47] = [
+    'い', 'ろ', 'は', 'に', 'ほ', 'へ', 'と', 'ち', 'り', 'ぬ', 'る', 'を', 'わ', 'か', 'よ',
+    'た', 'れ', 'そ', 'つ', 'ね', 'な', 'ら', 'む', 'う', 'ゐ', 'の', 'お', 'く', 'や', 'ま',
+    'け', 'ふ', 'こ', 'え', 'て', 'あ', 'さ', 'き', 'ゆ', 'め', 'み', 'し', 'ゑ',
+    'ひ', 'も', 'せ', 'す'
+];
+static KATAKANA: [char; 48] = [
+    'ア', 'イ', 'ウ', 'エ', 'オ', 'カ', 'キ', 'ク', 'ケ', 'コ', 'サ', 'シ', 'ス', 'セ', 'ソ',
+    'タ', 'チ', 'ツ', 'テ', 'ト', 'ナ', 'ニ', 'ヌ', 'ネ', 'ノ', 'ハ', 'ヒ', 'フ', 'ヘ', 'ホ',
+    'マ', 'ミ', 'ム', 'メ', 'モ', 'ヤ', 'ユ', 'ヨ', 'ラ', 'リ', 'ル', 'レ', 'ロ',
+    'ワ', 'ヰ', 'ヱ', 'ヲ', 'ン'
+];
+static KATAKANA_IROHA: [char; 47] = [
+    'イ', 'ロ', 'ハ', 'ニ', 'ホ', 'ヘ', 'ト', 'チ', 'リ', 'ヌ', 'ル', 'ヲ', 'ワ', 'カ', 'ヨ',
+    'タ', 'レ', 'ソ', 'ツ', 'ネ', 'ナ', 'ラ', 'ム', 'ウ', 'ヰ', 'ノ', 'オ', 'ク', 'ヤ', 'マ',
+    'ケ', 'フ', 'コ', 'エ', 'テ', 'ア', 'サ', 'キ', 'ユ', 'メ', 'ミ', 'シ', 'ヱ',
+    'ヒ', 'モ', 'セ', 'ス'
+];
+
+/// The generated content resolution traversal.
+pub struct ResolveGeneratedContent<'a> {
+    /// The layout context.
+    layout_context: &'a LayoutContext<'a>,
+    /// The counter representing an ordered list item.
+    list_item: Counter,
+    /// Named CSS counters.
+    counters: HashMap<String,Counter>,
+    /// The level of quote nesting.
+    quote: u32,
+}
+
+impl<'a> ResolveGeneratedContent<'a> {
+    /// Creates a new generated content resolution traversal.
+    pub fn new(layout_context: &'a LayoutContext<'a>) -> ResolveGeneratedContent<'a> {
+        ResolveGeneratedContent {
+            layout_context: layout_context,
+            list_item: Counter::new(),
+            counters: HashMap::new(),
+            quote: 0,
+        }
+    }
+}
+
+impl<'a> InorderFlowTraversal for ResolveGeneratedContent<'a> {
+    #[inline]
+    fn process(&mut self, flow: &mut Flow, level: u32) {
+        let mut mutator = ResolveGeneratedContentFragmentMutator {
+            traversal: self,
+            level: level,
+            is_block: flow.is_block_like(),
+            incremented: false,
+        };
+        flow.mutate_fragments(&mut |fragment| mutator.mutate_fragment(fragment))
+    }
+
+    #[inline]
+    fn should_process(&mut self, flow: &mut Flow) -> bool {
+        flow::base(flow).restyle_damage.intersects(RESOLVE_GENERATED_CONTENT) ||
+            flow::base(flow).flags.intersects(AFFECTS_COUNTERS | HAS_COUNTER_AFFECTING_CHILDREN)
+    }
+}
+
+/// The object that mutates the generated content fragments.
+struct ResolveGeneratedContentFragmentMutator<'a,'b:'a> {
+    /// The traversal.
+    traversal: &'a mut ResolveGeneratedContent<'b>,
+    /// The level we're at in the flow tree.
+    level: u32,
+    /// Whether this flow is a block flow.
+    is_block: bool,
+    /// Whether we've incremented the counter yet.
+    incremented: bool,
+}
+
+impl<'a,'b> ResolveGeneratedContentFragmentMutator<'a,'b> {
+    fn mutate_fragment(&mut self, fragment: &mut Fragment) {
+        // We only reset and/or increment counters once per flow. This avoids double-incrementing
+        // counters on list items (once for the main fragment and once for the marker).
+        if !self.incremented {
+            self.reset_and_increment_counters_as_necessary(fragment);
+        }
+
+        let mut list_style_type = fragment.style().get_list().list_style_type;
+        if fragment.style().get_box().display != display::T::list_item {
+            list_style_type = list_style_type::T::none
+        }
+
+        let mut new_info = None;
+        {
+            let info =
+                if let SpecificFragmentInfo::GeneratedContent(ref mut info) = fragment.specific {
+                    info
+                } else {
+                    return
+                };
+
+            match **info {
+                GeneratedContentInfo::ListItem => {
+                    new_info = self.traversal.list_item.render(self.traversal.layout_context,
+                                                               fragment.node,
+                                                               fragment.style.clone(),
+                                                               list_style_type,
+                                                               RenderingMode::Suffix(".\u{00a0}"))
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::String(_)) => {
+                    // Nothing to do here.
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::Counter(ref counter_name,
+                                                                       counter_style)) => {
+                    let mut temporary_counter = Counter::new();
+                    let counter = self.traversal
+                                      .counters
+                                      .get(counter_name.as_slice())
+                                      .unwrap_or(&mut temporary_counter);
+                    new_info = counter.render(self.traversal.layout_context,
+                                              fragment.node,
+                                              fragment.style.clone(),
+                                              counter_style,
+                                              RenderingMode::Plain)
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::Counters(ref counter_name,
+                                                                        ref separator,
+                                                                        counter_style)) => {
+                    let mut temporary_counter = Counter::new();
+                    let counter = self.traversal
+                                      .counters
+                                      .get(counter_name.as_slice())
+                                      .unwrap_or(&mut temporary_counter);
+                    new_info = counter.render(self.traversal.layout_context,
+                                              fragment.node,
+                                              fragment.style.clone(),
+                                              counter_style,
+                                              RenderingMode::All(separator.as_slice()));
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::OpenQuote) => {
+                    new_info = Some(render_text(self.traversal.layout_context,
+                                                fragment.node,
+                                                fragment.style.clone(),
+                                                self.quote(&*fragment.style, false)));
+                    self.traversal.quote += 1
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::CloseQuote) => {
+                    if self.traversal.quote >= 1 {
+                        self.traversal.quote -= 1
+                    }
+
+                    new_info = Some(render_text(self.traversal.layout_context,
+                                                fragment.node,
+                                                fragment.style.clone(),
+                                                self.quote(&*fragment.style, true)));
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::NoOpenQuote) => {
+                    self.traversal.quote += 1
+                }
+                GeneratedContentInfo::ContentItem(ContentItem::NoCloseQuote) => {
+                    if self.traversal.quote >= 1 {
+                        self.traversal.quote -= 1
+                    }
+                }
+            }
+        };
+
+        if let Some(new_info) = new_info {
+            fragment.specific = new_info
+        }
+    }
+
+    fn reset_and_increment_counters_as_necessary(&mut self, fragment: &mut Fragment) {
+        let mut list_style_type = fragment.style().get_list().list_style_type;
+        if !self.is_block || fragment.style().get_box().display != display::T::list_item {
+            list_style_type = list_style_type::T::none
+        }
+
+        match list_style_type {
+            list_style_type::T::disc | list_style_type::T::none | list_style_type::T::circle |
+            list_style_type::T::square | list_style_type::T::disclosure_open |
+            list_style_type::T::disclosure_closed => {}
+            _ => self.traversal.list_item.increment(self.level, 1),
+        }
+
+        // Truncate down counters.
+        for (_, counter) in self.traversal.counters.iter_mut() {
+            counter.truncate_to_level(self.level);
+        }
+        self.traversal.list_item.truncate_to_level(self.level);
+
+        for &(ref counter_name, value) in fragment.style().get_counters().counter_reset.0.iter() {
+            if let Some(ref mut counter) = self.traversal.counters.get_mut(counter_name) {
+                 counter.reset(self.level, value);
+                 continue
+            }
+
+            let mut counter = Counter::new();
+            counter.reset(self.level, value);
+            self.traversal.counters.insert((*counter_name).clone(), counter);
+        }
+
+        for &(ref counter_name, value) in fragment.style()
+                                                  .get_counters()
+                                                  .counter_increment
+                                                  .0
+                                                  .iter() {
+            if let Some(ref mut counter) = self.traversal.counters.get_mut(counter_name) {
+                counter.increment(self.level, value);
+                continue
+            }
+
+            let mut counter = Counter::new();
+            counter.increment(self.level, value);
+            self.traversal.counters.insert((*counter_name).clone(), counter);
+        }
+
+        self.incremented = true
+    }
+
+    fn quote(&self, style: &ComputedValues, close: bool) -> String {
+        let quotes = &style.get_list().quotes;
+        debug_assert!(!quotes.0.is_empty());
+        let &(ref open_quote, ref close_quote) =
+            if self.traversal.quote as uint >= quotes.0.len() {
+                quotes.0.last().unwrap()
+            } else {
+                &quotes.0[self.traversal.quote as uint]
+            };
+        if close {
+            close_quote.to_string()
+        } else {
+            open_quote.to_string()
+        }
+    }
+}
+
+/// A counter per CSS 2.1 § 12.4.
+struct Counter {
+    /// The values at each level.
+    values: Vec<CounterValue>,
+}
+
+impl Counter {
+    fn new() -> Counter {
+        Counter {
+            values: Vec::new(),
+        }
+    }
+
+    fn reset(&mut self, level: u32, value: i32) {
+        // Do we have an instance of the counter at this level? If so, just mutate it.
+        if let Some(ref mut existing_value) = self.values.last_mut() {
+            if level == existing_value.level {
+                existing_value.value = value;
+                return
+            }
+        }
+
+        // Otherwise, push a new instance of the counter.
+        self.values.push(CounterValue {
+            level: level,
+            value: value,
+        })
+    }
+
+    fn truncate_to_level(&mut self, level: u32) {
+        if let Some(position) = self.values.iter().position(|value| value.level > level) {
+            self.values.truncate(position)
+        }
+    }
+
+    fn increment(&mut self, level: u32, amount: i32) {
+        if let Some(ref mut value) = self.values.last_mut() {
+            value.value += amount;
+            return
+        }
+
+        self.values.push(CounterValue {
+            level: level,
+            value: amount,
+        })
+    }
+
+    fn render(&self,
+              layout_context: &LayoutContext,
+              node: OpaqueNode,
+              style: Arc<ComputedValues>,
+              list_style_type: list_style_type::T,
+              mode: RenderingMode)
+              -> Option<SpecificFragmentInfo> {
+        let mut string = String::new();
+        match mode {
+            RenderingMode::Plain => {
+                let value = match self.values.last() {
+                    Some(ref value) => value.value,
+                    None => 0,
+                };
+                push_representation(value, list_style_type, &mut string)
+            }
+            RenderingMode::Suffix(suffix) => {
+                let value = match self.values.last() {
+                    Some(ref value) => value.value,
+                    None => 0,
+                };
+                push_representation(value, list_style_type, &mut string);
+                string.push_str(suffix)
+            }
+            RenderingMode::All(separator) => {
+                let mut first = true;
+                for value in self.values.iter() {
+                    if !first {
+                        string.push_str(separator)
+                    }
+                    first = false;
+                    push_representation(value.value, list_style_type, &mut string)
+                }
+            }
+        }
+
+        if string.is_empty() {
+            None
+        } else {
+            Some(render_text(layout_context, node, style, string))
+        }
+    }
+}
+
+/// How a counter value is to be rendered.
+enum RenderingMode<'a> {
+    /// The innermost counter value is rendered with no extra decoration.
+    Plain,
+    /// The innermost counter value is rendered with the given string suffix.
+    Suffix(&'a str),
+    /// All values of the counter are rendered with the given separator string between them.
+    All(&'a str),
+}
+
+/// The value of a counter at a given level.
+struct CounterValue {
+    /// The level of the flow tree that this corresponds to.
+    level: u32,
+    /// The value of the counter at this level.
+    value: i32,
+}
+
+/// Creates fragment info for a literal string.
+fn render_text(layout_context: &LayoutContext,
+               node: OpaqueNode,
+               style: Arc<ComputedValues>,
+               string: String)
+               -> SpecificFragmentInfo {
+    let mut fragments = DList::new();
+    let info = SpecificFragmentInfo::UnscannedText(UnscannedTextFragmentInfo::from_text(string));
+    fragments.push_back(Fragment::from_opaque_node_and_style(node,
+                                                             style,
+                                                             incremental::rebuild_and_reflow(),
+                                                             info));
+    let fragments = TextRunScanner::new().scan_for_runs(layout_context.font_context(), fragments);
+    debug_assert!(fragments.len() == 1);
+    fragments.fragments.into_iter().next().unwrap().specific
+}
+
+/// Appends string that represents the value rendered using the system appropriate for the given
+/// `list-style-type` onto the given string.
+fn push_representation(value: i32, list_style_type: list_style_type::T, accumulator: &mut String) {
+    match list_style_type {
+        list_style_type::T::none => {}
+        list_style_type::T::disc |
+        list_style_type::T::circle |
+        list_style_type::T::square |
+        list_style_type::T::disclosure_open |
+        list_style_type::T::disclosure_closed => {
+            accumulator.push(static_representation(list_style_type))
+        }
+        list_style_type::T::decimal => push_numeric_representation(value, &DECIMAL, accumulator),
+        list_style_type::T::arabic_indic => {
+            push_numeric_representation(value, &ARABIC_INDIC, accumulator)
+        }
+        list_style_type::T::bengali => push_numeric_representation(value, &BENGALI, accumulator),
+        list_style_type::T::cambodian | list_style_type::T::khmer => {
+            push_numeric_representation(value, &CAMBODIAN, accumulator)
+        }
+        list_style_type::T::cjk_decimal => {
+            push_numeric_representation(value, &CJK_DECIMAL, accumulator)
+        }
+        list_style_type::T::devanagari => {
+            push_numeric_representation(value, &DEVANAGARI, accumulator)
+        }
+        list_style_type::T::gujarati => push_numeric_representation(value, &GUJARATI, accumulator),
+        list_style_type::T::gurmukhi => push_numeric_representation(value, &GURMUKHI, accumulator),
+        list_style_type::T::kannada => push_numeric_representation(value, &KANNADA, accumulator),
+        list_style_type::T::lao => push_numeric_representation(value, &LAO, accumulator),
+        list_style_type::T::malayalam => {
+            push_numeric_representation(value, &MALAYALAM, accumulator)
+        }
+        list_style_type::T::mongolian => {
+            push_numeric_representation(value, &MONGOLIAN, accumulator)
+        }
+        list_style_type::T::myanmar => push_numeric_representation(value, &MYANMAR, accumulator),
+        list_style_type::T::oriya => push_numeric_representation(value, &ORIYA, accumulator),
+        list_style_type::T::persian => push_numeric_representation(value, &PERSIAN, accumulator),
+        list_style_type::T::telugu => push_numeric_representation(value, &TELUGU, accumulator),
+        list_style_type::T::thai => push_numeric_representation(value, &THAI, accumulator),
+        list_style_type::T::tibetan => push_numeric_representation(value, &TIBETAN, accumulator),
+        list_style_type::T::lower_alpha => {
+            push_alphabetic_representation(value, &LOWER_ALPHA, accumulator)
+        }
+        list_style_type::T::upper_alpha => {
+            push_alphabetic_representation(value, &UPPER_ALPHA, accumulator)
+        }
+        list_style_type::T::cjk_earthly_branch => {
+            push_alphabetic_representation(value, &CJK_EARTHLY_BRANCH, accumulator)
+        }
+        list_style_type::T::cjk_heavenly_stem => {
+            push_alphabetic_representation(value, &CJK_HEAVENLY_STEM, accumulator)
+        }
+        list_style_type::T::lower_greek => {
+            push_alphabetic_representation(value, &LOWER_GREEK, accumulator)
+        }
+        list_style_type::T::hiragana => {
+            push_alphabetic_representation(value, &HIRAGANA, accumulator)
+        }
+        list_style_type::T::hiragana_iroha => {
+            push_alphabetic_representation(value, &HIRAGANA_IROHA, accumulator)
+        }
+        list_style_type::T::katakana => {
+            push_alphabetic_representation(value, &KATAKANA, accumulator)
+        }
+        list_style_type::T::katakana_iroha => {
+            push_alphabetic_representation(value, &KATAKANA_IROHA, accumulator)
+        }
+    }
+}
+
+/// Returns the static character that represents the value rendered using the given list-style, if
+/// possible.
+pub fn static_representation(list_style_type: list_style_type::T) -> char {
+    match list_style_type {
+        list_style_type::T::disc => '•',
+        list_style_type::T::circle => '◦',
+        list_style_type::T::square => '▪',
+        list_style_type::T::disclosure_open => '▾',
+        list_style_type::T::disclosure_closed => '‣',
+        _ => panic!("No static representation for this list-style-type!"),
+    }
+}
+
+/// Pushes the string that represents the value rendered using the given *alphabetic system* onto
+/// the accumulator per CSS-COUNTER-STYLES § 3.1.4.
+fn push_alphabetic_representation(mut value: i32, system: &[char], accumulator: &mut String) {
+    let mut string = SmallVec8::new();
+    while value != 0 {
+        // Step 1.
+        value = value - 1;
+        // Step 2.
+        string.push(system[(value as uint) % system.len()]);
+        // Step 3.
+        value = ((value as uint) / system.len()) as i32;
+    }
+
+    for i in range(0, string.len()).rev() {
+        accumulator.push(*string.get(i))
+    }
+}
+
+/// Pushes the string that represents the value rendered using the given *numeric system* onto the
+/// accumulator per CSS-COUNTER-STYLES § 3.1.4.
+fn push_numeric_representation(mut value: i32, system: &[char], accumulator: &mut String) {
+    // Step 1.
+    if value == 0 {
+        accumulator.push(system[0]);
+        return
+    }
+
+    // Step 2.
+    let mut string = SmallVec8::new();
+    while value != 0 {
+        // Step 2.1.
+        string.push(system[(value as uint) % system.len()]);
+        // Step 2.2.
+        value = ((value as uint) / system.len()) as i32;
+    }
+
+    // Step 3.
+    for &ch in string.iter().rev() {
+        accumulator.push(ch)
+    }
+}
+
diff --git a/components/layout/incremental.rs b/components/layout/incremental.rs
index b163a8fbf29..9d989c7b65a 100644
--- a/components/layout/incremental.rs
+++ b/components/layout/incremental.rs
@@ -2,8 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use flow::{self, Flow};
-use flow::{IS_ABSOLUTELY_POSITIONED};
+use flow::{self, AFFECTS_COUNTERS, Flow, HAS_COUNTER_AFFECTING_CHILDREN, IS_ABSOLUTELY_POSITIONED};
 
 use std::fmt;
 use std::sync::Arc;
@@ -32,8 +31,12 @@ bitflags! {
         #[doc = "top-down."]
         const REFLOW = 0x08,
 
+        #[doc = "Re-resolve generated content. \
+                 Propagates up the flow tree because the computation is inorder."]
+        const RESOLVE_GENERATED_CONTENT = 0x10,
+
         #[doc = "The entire flow needs to be reconstructed."]
-        const RECONSTRUCT_FLOW = 0x10
+        const RECONSTRUCT_FLOW = 0x20
     }
 }
 
@@ -50,9 +53,9 @@ impl RestyleDamage {
     /// we should add to the *parent* of this flow.
     pub fn damage_for_parent(self, child_is_absolutely_positioned: bool) -> RestyleDamage {
         if child_is_absolutely_positioned {
-            self & (REPAINT | REFLOW_OUT_OF_FLOW)
+            self & (REPAINT | REFLOW_OUT_OF_FLOW | RESOLVE_GENERATED_CONTENT)
         } else {
-            self & (REPAINT | REFLOW | REFLOW_OUT_OF_FLOW)
+            self & (REPAINT | REFLOW | REFLOW_OUT_OF_FLOW | RESOLVE_GENERATED_CONTENT)
         }
     }
 
@@ -91,10 +94,11 @@ impl fmt::Debug for RestyleDamage {
         let mut first_elem = true;
 
         let to_iter =
-            [ (REPAINT,         "Repaint")
-            , (BUBBLE_ISIZES,    "BubbleISizes")
+            [ (REPAINT, "Repaint")
+            , (BUBBLE_ISIZES, "BubbleISizes")
             , (REFLOW_OUT_OF_FLOW, "ReflowOutOfFlow")
-            , (REFLOW,          "Reflow")
+            , (REFLOW, "Reflow")
+            , (RESOLVE_GENERATED_CONTENT, "ResolveGeneratedContent")
             , (RECONSTRUCT_FLOW, "ReconstructFlow")
             ];
 
@@ -126,10 +130,18 @@ macro_rules! add_if_not_equal(
     })
 );
 
+/// Returns a bitmask that represents a flow that needs to be rebuilt and reflowed.
+///
+/// Use this instead of `RestyleDamage::all()` because `RestyleDamage::all()` will result in
+/// unnecessary sequential resolution of generated content.
+pub fn rebuild_and_reflow() -> RestyleDamage {
+    REPAINT | BUBBLE_ISIZES | REFLOW_OUT_OF_FLOW | REFLOW | RECONSTRUCT_FLOW
+}
+
 pub fn compute_damage(old: &Option<Arc<ComputedValues>>, new: &ComputedValues) -> RestyleDamage {
     let old: &ComputedValues =
         match old.as_ref() {
-            None => return RestyleDamage::all(),
+            None => return rebuild_and_reflow(),
             Some(cv) => &**cv,
         };
 
@@ -186,6 +198,9 @@ impl<'a> LayoutDamageComputation for &'a mut (Flow + 'a) {
         let mut special_damage = SpecialRestyleDamage::empty();
         let is_absolutely_positioned = flow::base(self).flags.contains(IS_ABSOLUTELY_POSITIONED);
 
+        // In addition to damage, we use this phase to compute whether nodes affect CSS counters.
+        let mut has_counter_affecting_children = false;
+
         {
             let self_base = flow::mut_base(self);
             for kid in self_base.children.iter_mut() {
@@ -199,21 +214,32 @@ impl<'a> LayoutDamageComputation for &'a mut (Flow + 'a) {
                 self_base.restyle_damage
                          .insert(flow::base(kid).restyle_damage.damage_for_parent(
                                  child_is_absolutely_positioned));
+
+                has_counter_affecting_children = has_counter_affecting_children ||
+                    flow::base(kid).flags.intersects(AFFECTS_COUNTERS |
+                                                     HAS_COUNTER_AFFECTING_CHILDREN);
+
             }
         }
 
-        let self_base = flow::base(self);
+        let self_base = flow::mut_base(self);
         if self_base.flags.float_kind() != float::T::none &&
                 self_base.restyle_damage.intersects(REFLOW) {
             special_damage.insert(REFLOW_ENTIRE_DOCUMENT);
         }
 
+        if has_counter_affecting_children {
+            self_base.flags.insert(HAS_COUNTER_AFFECTING_CHILDREN)
+        } else {
+            self_base.flags.remove(HAS_COUNTER_AFFECTING_CHILDREN)
+        }
+
         special_damage
     }
 
     fn reflow_entire_document(self) {
         let self_base = flow::mut_base(self);
-        self_base.restyle_damage.insert(RestyleDamage::all());
+        self_base.restyle_damage.insert(rebuild_and_reflow());
         self_base.restyle_damage.remove(RECONSTRUCT_FLOW);
         for kid in self_base.children.iter_mut() {
             kid.reflow_entire_document();
diff --git a/components/layout/inline.rs b/components/layout/inline.rs
index 679a8eae608..5fb3ec9f180 100644
--- a/components/layout/inline.rs
+++ b/components/layout/inline.rs
@@ -12,9 +12,8 @@ use flow::{BaseFlow, FlowClass, Flow, MutableFlowUtils, ForceNonfloatedFlag};
 use flow::{IS_ABSOLUTELY_POSITIONED};
 use flow;
 use fragment::{CoordinateSystem, Fragment, FragmentBorderBoxIterator, ScannedTextFragmentInfo};
-use fragment::{SpecificFragmentInfo};
-use fragment::SplitInfo;
-use incremental::{REFLOW, REFLOW_OUT_OF_FLOW};
+use fragment::{SpecificFragmentInfo, SplitInfo};
+use incremental::{REFLOW, REFLOW_OUT_OF_FLOW, RESOLVE_GENERATED_CONTENT};
 use layout_debug;
 use model::IntrinsicISizesContribution;
 use text;
@@ -789,14 +788,22 @@ pub struct InlineFlow {
 
 impl InlineFlow {
     pub fn from_fragments(fragments: InlineFragments, writing_mode: WritingMode) -> InlineFlow {
-        InlineFlow {
+        let mut flow = InlineFlow {
             base: BaseFlow::new(None, writing_mode, ForceNonfloatedFlag::ForceNonfloated),
             fragments: fragments,
             lines: Vec::new(),
             minimum_block_size_above_baseline: Au(0),
             minimum_depth_below_baseline: Au(0),
             first_line_indentation: Au(0),
+        };
+
+        for fragment in flow.fragments.fragments.iter() {
+            if fragment.is_generated_content() {
+                flow.base.restyle_damage.insert(RESOLVE_GENERATED_CONTENT)
+            }
         }
+
+        flow
     }
 
     /// Returns the distance from the baseline for the logical block-start inline-start corner of
@@ -1399,6 +1406,12 @@ impl Flow for InlineFlow {
                                       .translate(stacking_context_position))
         }
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        for fragment in self.fragments.fragments.iter_mut() {
+            (*mutator)(fragment)
+        }
+    }
 }
 
 impl fmt::Debug for InlineFlow {
diff --git a/components/layout/layout_task.rs b/components/layout/layout_task.rs
index 793bc083723..3e80d90639b 100644
--- a/components/layout/layout_task.rs
+++ b/components/layout/layout_task.rs
@@ -840,6 +840,14 @@ impl LayoutTask {
             layout_debug::begin_trace(layout_root.clone());
         }
 
+        // Resolve generated content.
+        profile(TimeProfilerCategory::LayoutGeneratedContent,
+                self.profiler_metadata(data),
+                self.time_profiler_chan.clone(),
+                || {
+                    sequential::resolve_generated_content(&mut layout_root, &shared_layout_context)
+                });
+
         // Perform the primary layout passes over the flow tree to compute the locations of all
         // the boxes.
         profile(TimeProfilerCategory::LayoutMain,
diff --git a/components/layout/lib.rs b/components/layout/lib.rs
index 6eb177f6f94..00bd3896af5 100644
--- a/components/layout/lib.rs
+++ b/components/layout/lib.rs
@@ -67,7 +67,9 @@ pub mod flow;
 pub mod flow_list;
 pub mod flow_ref;
 pub mod fragment;
+pub mod generated_content;
 pub mod layout_task;
+pub mod incremental;
 pub mod inline;
 pub mod list_item;
 pub mod model;
@@ -83,7 +85,6 @@ pub mod table_row;
 pub mod table_cell;
 pub mod text;
 pub mod traversal;
-pub mod incremental;
 pub mod wrapper;
 
 pub mod css {
diff --git a/components/layout/list_item.rs b/components/layout/list_item.rs
index 84c713af944..e7c90257ccd 100644
--- a/components/layout/list_item.rs
+++ b/components/layout/list_item.rs
@@ -8,12 +8,13 @@
 #![deny(unsafe_blocks)]
 
 use block::BlockFlow;
-use construct::FlowConstructor;
 use context::LayoutContext;
 use display_list_builder::ListItemFlowDisplayListBuilding;
 use floats::FloatKind;
 use flow::{Flow, FlowClass};
-use fragment::{Fragment, FragmentBorderBoxIterator};
+use fragment::{CoordinateSystem, Fragment, FragmentBorderBoxIterator, GeneratedContentInfo};
+use generated_content;
+use incremental::RESOLVE_GENERATED_CONTENT;
 use wrapper::ThreadSafeLayoutNode;
 
 use geom::{Point2D, Rect};
@@ -36,19 +37,33 @@ pub struct ListItemFlow {
 }
 
 impl ListItemFlow {
-    pub fn from_node_marker_and_flotation(constructor: &mut FlowConstructor,
-                                          node: &ThreadSafeLayoutNode,
-                                          marker_fragment: Option<Fragment>,
-                                          flotation: Option<FloatKind>)
-                                          -> ListItemFlow {
-        ListItemFlow {
+    pub fn from_node_fragments_and_flotation(node: &ThreadSafeLayoutNode,
+                                             main_fragment: Fragment,
+                                             marker_fragment: Option<Fragment>,
+                                             flotation: Option<FloatKind>)
+                                             -> ListItemFlow {
+        let mut this = ListItemFlow {
             block_flow: if let Some(flotation) = flotation {
-                BlockFlow::float_from_node(constructor, node, flotation)
+                BlockFlow::float_from_node_and_fragment(node, main_fragment, flotation)
             } else {
-                BlockFlow::from_node(constructor, node)
+                BlockFlow::from_node_and_fragment(node, main_fragment)
             },
             marker: marker_fragment,
+        };
+
+        if let Some(ref marker) = this.marker {
+            match marker.style().get_list().list_style_type {
+                list_style_type::T::disc |
+                list_style_type::T::none |
+                list_style_type::T::circle |
+                list_style_type::T::square |
+                list_style_type::T::disclosure_open |
+                list_style_type::T::disclosure_closed => {}
+                _ => this.block_flow.base.restyle_damage.insert(RESOLVE_GENERATED_CONTENT),
+            }
         }
+
+        this
     }
 }
 
@@ -134,24 +149,59 @@ impl Flow for ListItemFlow {
     fn iterate_through_fragment_border_boxes(&self,
                                              iterator: &mut FragmentBorderBoxIterator,
                                              stacking_context_position: &Point2D<Au>) {
-        self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
+        self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position);
+
+        if let Some(ref marker) = self.marker {
+            if iterator.should_process(marker) {
+                iterator.process(
+                    marker,
+                    &marker.stacking_relative_border_box(&self.block_flow
+                                                              .base
+                                                              .stacking_relative_position,
+                                                         &self.block_flow
+                                                              .base
+                                                              .absolute_position_info
+                                                              .relative_containing_block_size,
+                                                         self.block_flow
+                                                             .base
+                                                             .absolute_position_info
+                                                             .relative_containing_block_mode,
+                                                         CoordinateSystem::Parent)
+                           .translate(stacking_context_position));
+            }
+        }
+    }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator);
+
+        if let Some(ref mut marker) = self.marker {
+            (*mutator)(marker)
+        }
     }
 }
 
-/// Returns the static text to be used for the given value of the `list-style-type` property.
-///
-/// TODO(pcwalton): Return either a string or a counter descriptor, once we support counters.
-pub fn static_text_for_list_style_type(list_style_type: list_style_type::T)
-                                       -> Option<&'static str> {
-    // Just to keep things simple, use a nonbreaking space (Unicode 0xa0) to provide the marker
-    // separation.
-    match list_style_type {
-        list_style_type::T::none => None,
-        list_style_type::T::disc => Some("•\u{a0}"),
-        list_style_type::T::circle => Some("◦\u{a0}"),
-        list_style_type::T::square => Some("▪\u{a0}"),
-        list_style_type::T::disclosure_open => Some("▾\u{a0}"),
-        list_style_type::T::disclosure_closed => Some("‣\u{a0}"),
+/// The kind of content that `list-style-type` results in.
+pub enum ListStyleTypeContent {
+    None,
+    StaticText(char),
+    GeneratedContent(Box<GeneratedContentInfo>),
+}
+
+impl ListStyleTypeContent {
+    /// Returns the content to be used for the given value of the `list-style-type` property.
+    pub fn from_list_style_type(list_style_type: list_style_type::T) -> ListStyleTypeContent {
+        // Just to keep things simple, use a nonbreaking space (Unicode 0xa0) to provide the marker
+        // separation.
+        match list_style_type {
+            list_style_type::T::none => ListStyleTypeContent::None,
+            list_style_type::T::disc | list_style_type::T::circle | list_style_type::T::square |
+            list_style_type::T::disclosure_open | list_style_type::T::disclosure_closed => {
+                let text = generated_content::static_representation(list_style_type);
+                ListStyleTypeContent::StaticText(text)
+            }
+            _ => ListStyleTypeContent::GeneratedContent(box GeneratedContentInfo::ListItem),
+        }
     }
 }
 
diff --git a/components/layout/sequential.rs b/components/layout/sequential.rs
index 7007fdfa427..3c4755c8e0c 100644
--- a/components/layout/sequential.rs
+++ b/components/layout/sequential.rs
@@ -5,10 +5,11 @@
 //! Implements sequential traversals over the DOM and flow trees.
 
 use context::{LayoutContext, SharedLayoutContext};
-use flow::{self, Flow, ImmutableFlowUtils, MutableFlowUtils, PostorderFlowTraversal};
-use flow::{PreorderFlowTraversal};
+use flow::{self, Flow, ImmutableFlowUtils, InorderFlowTraversal, MutableFlowUtils};
+use flow::{PostorderFlowTraversal, PreorderFlowTraversal};
 use flow_ref::FlowRef;
 use fragment::FragmentBorderBoxIterator;
+use generated_content::ResolveGeneratedContent;
 use traversal::{BubbleISizes, RecalcStyleForNode, ConstructFlows};
 use traversal::{AssignBSizesAndStoreOverflow, AssignISizes};
 use traversal::{ComputeAbsolutePositions, BuildDisplayList};
@@ -39,6 +40,24 @@ pub fn traverse_dom_preorder(root: LayoutNode,
     doit(root, recalc_style, construct_flows);
 }
 
+pub fn resolve_generated_content(root: &mut FlowRef, shared_layout_context: &SharedLayoutContext) {
+    fn doit(flow: &mut Flow, level: u32, traversal: &mut ResolveGeneratedContent) {
+        if !traversal.should_process(flow) {
+            return
+        }
+
+        traversal.process(flow, level);
+
+        for kid in flow::mut_base(flow).children.iter_mut() {
+            doit(kid, level + 1, traversal)
+        }
+    }
+
+    let layout_context = LayoutContext::new(shared_layout_context);
+    let mut traversal = ResolveGeneratedContent::new(&layout_context);
+    doit(&mut **root, 0, &mut traversal)
+}
+
 pub fn traverse_flow_tree_preorder(root: &mut FlowRef,
                                    shared_layout_context: &SharedLayoutContext) {
     fn doit(flow: &mut Flow,
diff --git a/components/layout/table.rs b/components/layout/table.rs
index 9679938b2e7..a1fa55889ea 100644
--- a/components/layout/table.rs
+++ b/components/layout/table.rs
@@ -8,7 +8,6 @@
 
 use block::{BlockFlow, ISizeAndMarginsComputer, MarginsMayCollapseFlag};
 use block::{ISizeConstraintInput, ISizeConstraintSolution};
-use construct::FlowConstructor;
 use context::LayoutContext;
 use floats::FloatKind;
 use flow::{self, Flow, FlowClass, IMPACTED_BY_LEFT_FLOATS, IMPACTED_BY_RIGHT_FLOATS};
@@ -55,30 +54,12 @@ impl TableFlow {
                                   fragment: Fragment)
                                   -> TableFlow {
         let mut block_flow = BlockFlow::from_node_and_fragment(node, fragment);
-        let table_layout = if block_flow.fragment().style().get_table().table_layout ==
-                              table_layout::T::fixed {
-            TableLayout::Fixed
-        } else {
-            TableLayout::Auto
-        };
-        TableFlow {
-            block_flow: block_flow,
-            column_intrinsic_inline_sizes: Vec::new(),
-            column_computed_inline_sizes: Vec::new(),
-            table_layout: table_layout
-        }
-    }
-
-    pub fn from_node(constructor: &mut FlowConstructor,
-                     node: &ThreadSafeLayoutNode)
-                     -> TableFlow {
-        let mut block_flow = BlockFlow::from_node(constructor, node);
-        let table_layout = if block_flow.fragment().style().get_table().table_layout ==
-                              table_layout::T::fixed {
-            TableLayout::Fixed
-        } else {
-            TableLayout::Auto
-        };
+        let table_layout =
+            if block_flow.fragment().style().get_table().table_layout == table_layout::T::fixed {
+                TableLayout::Fixed
+            } else {
+                TableLayout::Auto
+            };
         TableFlow {
             block_flow: block_flow,
             column_intrinsic_inline_sizes: Vec::new(),
@@ -87,17 +68,17 @@ impl TableFlow {
         }
     }
 
-    pub fn float_from_node(constructor: &mut FlowConstructor,
-                           node: &ThreadSafeLayoutNode,
-                           float_kind: FloatKind)
-                           -> TableFlow {
-        let mut block_flow = BlockFlow::float_from_node(constructor, node, float_kind);
-        let table_layout = if block_flow.fragment().style().get_table().table_layout ==
-                              table_layout::T::fixed {
-            TableLayout::Fixed
-        } else {
-            TableLayout::Auto
-        };
+    pub fn float_from_node_and_fragment(node: &ThreadSafeLayoutNode,
+                                        fragment: Fragment,
+                                        float_kind: FloatKind)
+                                        -> TableFlow {
+        let mut block_flow = BlockFlow::float_from_node_and_fragment(node, fragment, float_kind);
+        let table_layout =
+            if block_flow.fragment().style().get_table().table_layout == table_layout::T::fixed {
+                TableLayout::Fixed
+            } else {
+                TableLayout::Auto
+            };
         TableFlow {
             block_flow: block_flow,
             column_intrinsic_inline_sizes: Vec::new(),
@@ -396,6 +377,10 @@ impl Flow for TableFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableFlow {
diff --git a/components/layout/table_caption.rs b/components/layout/table_caption.rs
index ceb6bf7e3aa..b0b08e7cdec 100644
--- a/components/layout/table_caption.rs
+++ b/components/layout/table_caption.rs
@@ -7,10 +7,9 @@
 #![deny(unsafe_blocks)]
 
 use block::BlockFlow;
-use construct::FlowConstructor;
 use context::LayoutContext;
 use flow::{FlowClass, Flow};
-use fragment::FragmentBorderBoxIterator;
+use fragment::{Fragment, FragmentBorderBoxIterator};
 use wrapper::ThreadSafeLayoutNode;
 
 use geom::{Point2D, Rect};
@@ -26,11 +25,10 @@ pub struct TableCaptionFlow {
 }
 
 impl TableCaptionFlow {
-    pub fn from_node(constructor: &mut FlowConstructor,
-                     node: &ThreadSafeLayoutNode)
-                     -> TableCaptionFlow {
+    pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode, fragment: Fragment)
+                                  -> TableCaptionFlow {
         TableCaptionFlow {
-            block_flow: BlockFlow::from_node(constructor, node)
+            block_flow: BlockFlow::from_node_and_fragment(node, fragment)
         }
     }
 }
@@ -96,6 +94,10 @@ impl Flow for TableCaptionFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableCaptionFlow {
diff --git a/components/layout/table_cell.rs b/components/layout/table_cell.rs
index f018e72c2c3..1c80c2a8f2c 100644
--- a/components/layout/table_cell.rs
+++ b/components/layout/table_cell.rs
@@ -178,6 +178,10 @@ impl Flow for TableCellFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableCellFlow {
diff --git a/components/layout/table_colgroup.rs b/components/layout/table_colgroup.rs
index f0ad4cff9ca..61008cd2506 100644
--- a/components/layout/table_colgroup.rs
+++ b/components/layout/table_colgroup.rs
@@ -104,6 +104,8 @@ impl Flow for TableColGroupFlow {
     fn iterate_through_fragment_border_boxes(&self,
                                              _: &mut FragmentBorderBoxIterator,
                                              _: &Point2D<Au>) {}
+
+    fn mutate_fragments(&mut self, _: &mut FnMut(&mut Fragment)) {}
 }
 
 impl fmt::Debug for TableColGroupFlow {
diff --git a/components/layout/table_row.rs b/components/layout/table_row.rs
index 3f07e401afb..1e45ba48fc1 100644
--- a/components/layout/table_row.rs
+++ b/components/layout/table_row.rs
@@ -8,10 +8,8 @@
 
 use block::BlockFlow;
 use block::ISizeAndMarginsComputer;
-use construct::FlowConstructor;
 use context::LayoutContext;
-use flow::{FlowClass, Flow, ImmutableFlowUtils};
-use flow;
+use flow::{self, FlowClass, Flow, ImmutableFlowUtils};
 use fragment::{Fragment, FragmentBorderBoxIterator};
 use layout_debug;
 use table::{ColumnComputedInlineSize, ColumnIntrinsicInlineSize, InternalTable};
@@ -49,8 +47,7 @@ pub struct CellIntrinsicInlineSize {
 }
 
 impl TableRowFlow {
-    pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode,
-                                  fragment: Fragment)
+    pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode, fragment: Fragment)
                                   -> TableRowFlow {
         TableRowFlow {
             block_flow: BlockFlow::from_node_and_fragment(node, fragment),
@@ -59,16 +56,6 @@ impl TableRowFlow {
         }
     }
 
-    pub fn from_node(constructor: &mut FlowConstructor,
-                     node: &ThreadSafeLayoutNode)
-                     -> TableRowFlow {
-        TableRowFlow {
-            block_flow: BlockFlow::from_node(constructor, node),
-            cell_intrinsic_inline_sizes: Vec::new(),
-            column_computed_inline_sizes: Vec::new()
-        }
-    }
-
     pub fn fragment<'a>(&'a mut self) -> &'a Fragment {
         &self.block_flow.fragment
     }
@@ -331,6 +318,10 @@ impl Flow for TableRowFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableRowFlow {
diff --git a/components/layout/table_rowgroup.rs b/components/layout/table_rowgroup.rs
index 1596e1bfab0..6ea1c4aaa18 100644
--- a/components/layout/table_rowgroup.rs
+++ b/components/layout/table_rowgroup.rs
@@ -7,7 +7,6 @@
 #![deny(unsafe_blocks)]
 
 use block::{BlockFlow, ISizeAndMarginsComputer, MarginsMayCollapseFlag};
-use construct::FlowConstructor;
 use context::LayoutContext;
 use flow::{FlowClass, Flow};
 use fragment::{Fragment, FragmentBorderBoxIterator};
@@ -45,15 +44,6 @@ impl TableRowGroupFlow {
         }
     }
 
-    pub fn from_node(constructor: &mut FlowConstructor, node: &ThreadSafeLayoutNode)
-                     -> TableRowGroupFlow {
-        TableRowGroupFlow {
-            block_flow: BlockFlow::from_node(constructor, node),
-            column_intrinsic_inline_sizes: Vec::new(),
-            column_computed_inline_sizes: Vec::new(),
-        }
-    }
-
     pub fn fragment<'a>(&'a mut self) -> &'a Fragment {
         &self.block_flow.fragment
     }
@@ -165,6 +155,10 @@ impl Flow for TableRowGroupFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableRowGroupFlow {
diff --git a/components/layout/table_wrapper.rs b/components/layout/table_wrapper.rs
index 0d2b6267806..042c08b5ed3 100644
--- a/components/layout/table_wrapper.rs
+++ b/components/layout/table_wrapper.rs
@@ -13,8 +13,8 @@
 
 #![deny(unsafe_blocks)]
 
-use block::{BlockFlow, BlockNonReplaced, FloatNonReplaced, ISizeAndMarginsComputer, MarginsMayCollapseFlag};
-use construct::FlowConstructor;
+use block::{BlockFlow, BlockNonReplaced, FloatNonReplaced, ISizeAndMarginsComputer};
+use block::{MarginsMayCollapseFlag};
 use context::LayoutContext;
 use floats::FloatKind;
 use flow::{FlowClass, Flow, ImmutableFlowUtils};
@@ -70,23 +70,6 @@ impl TableWrapperFlow {
         }
     }
 
-    pub fn from_node(constructor: &mut FlowConstructor,
-                     node: &ThreadSafeLayoutNode)
-                     -> TableWrapperFlow {
-        let mut block_flow = BlockFlow::from_node(constructor, node);
-        let table_layout = if block_flow.fragment().style().get_table().table_layout ==
-                              table_layout::T::fixed {
-            TableLayout::Fixed
-        } else {
-            TableLayout::Auto
-        };
-        TableWrapperFlow {
-            block_flow: block_flow,
-            column_intrinsic_inline_sizes: vec!(),
-            table_layout: table_layout
-        }
-    }
-
     pub fn float_from_node_and_fragment(node: &ThreadSafeLayoutNode,
                                         fragment: Fragment,
                                         float_kind: FloatKind)
@@ -383,6 +366,10 @@ impl Flow for TableWrapperFlow {
                                              stacking_context_position: &Point2D<Au>) {
         self.block_flow.iterate_through_fragment_border_boxes(iterator, stacking_context_position)
     }
+
+    fn mutate_fragments(&mut self, mutator: &mut FnMut(&mut Fragment)) {
+        self.block_flow.mutate_fragments(mutator)
+    }
 }
 
 impl fmt::Debug for TableWrapperFlow {
diff --git a/components/layout/traversal.rs b/components/layout/traversal.rs
index a31f6c9d3b6..228fdd6e7f0 100644
--- a/components/layout/traversal.rs
+++ b/components/layout/traversal.rs
@@ -13,7 +13,7 @@ use context::LayoutContext;
 use flow::{Flow, MutableFlowUtils};
 use flow::{PreorderFlowTraversal, PostorderFlowTraversal};
 use flow;
-use incremental::{RestyleDamage, BUBBLE_ISIZES, REFLOW, REFLOW_OUT_OF_FLOW};
+use incremental::{self, BUBBLE_ISIZES, REFLOW, REFLOW_OUT_OF_FLOW, RestyleDamage};
 use wrapper::{layout_node_to_unsafe_layout_node, LayoutNode};
 use wrapper::{PostorderNodeMutTraversal, ThreadSafeLayoutNode, UnsafeLayoutNode};
 use wrapper::{PreorderDomTraversal, PostorderDomTraversal};
@@ -171,7 +171,8 @@ impl<'a> PreorderDomTraversal for RecalcStyleForNode<'a> {
                                         &mut applicable_declarations,
                                         &mut shareable);
                     } else {
-                        ThreadSafeLayoutNode::new(&node).set_restyle_damage(RestyleDamage::all())
+                        ThreadSafeLayoutNode::new(&node).set_restyle_damage(
+                            incremental::rebuild_and_reflow())
                     }
 
                     // Perform the CSS cascade.
@@ -377,3 +378,4 @@ impl<'a> PostorderFlowTraversal for BuildDisplayList<'a> {
         flow.build_display_list(self.layout_context);
     }
 }
+
diff --git a/components/layout/wrapper.rs b/components/layout/wrapper.rs
index 74b3d20ca1c..bc89f74ea1b 100644
--- a/components/layout/wrapper.rs
+++ b/components/layout/wrapper.rs
@@ -67,9 +67,11 @@ use std::marker::ContravariantLifetime;
 use std::mem;
 use std::sync::mpsc::Sender;
 use string_cache::{Atom, Namespace};
+use style::computed_values::content::ContentItem;
 use style::computed_values::{content, display, white_space};
 use selectors::parser::{NamespaceConstraint, AttrSelector};
-use style::legacy::{LengthAttribute, SimpleColorAttribute, UnsignedIntegerAttribute, IntegerAttribute};
+use style::legacy::{IntegerAttribute, LengthAttribute, SimpleColorAttribute};
+use style::legacy::{UnsignedIntegerAttribute};
 use style::node::{TElement, TElementAttributes, TNode};
 use style::properties::PropertyDeclarationBlock;
 use url::Url;
@@ -154,10 +156,11 @@ pub trait TLayoutNode {
         }
     }
 
-    /// If this is a text node, copies out the text. If this is not a text node, fails.
+    /// If this is a text node or generated content, copies out its content. If this is not a text
+    /// node, fails.
     ///
-    /// FIXME(pcwalton): Don't copy text. Atomically reference count instead.
-    fn text(&self) -> String;
+    /// FIXME(pcwalton): This might have too much copying and/or allocation. Profile this.
+    fn text_content(&self) -> Vec<ContentItem>;
 
     /// Returns the first child of this node.
     fn first_child(&self) -> Option<Self>;
@@ -214,19 +217,25 @@ impl<'ln> TLayoutNode for LayoutNode<'ln> {
         }
     }
 
-    fn text(&self) -> String {
+    fn text_content(&self) -> Vec<ContentItem> {
         unsafe {
             let text: Option<LayoutJS<Text>> = TextCast::to_layout_js(self.get_jsmanaged());
             if let Some(text) = text {
-                return (*text.unsafe_get()).characterdata().data_for_layout().to_owned();
+                return vec![
+                    ContentItem::String((*text.unsafe_get()).characterdata()
+                                                            .data_for_layout()
+                                                            .to_owned())
+                ];
             }
-            let input: Option<LayoutJS<HTMLInputElement>> = HTMLInputElementCast::to_layout_js(self.get_jsmanaged());
+            let input: Option<LayoutJS<HTMLInputElement>> =
+                HTMLInputElementCast::to_layout_js(self.get_jsmanaged());
             if let Some(input) = input {
-                return input.get_value_for_layout();
+                return vec![ContentItem::String(input.get_value_for_layout())];
             }
-            let area: Option<LayoutJS<HTMLTextAreaElement>> = HTMLTextAreaElementCast::to_layout_js(self.get_jsmanaged());
+            let area: Option<LayoutJS<HTMLTextAreaElement>> =
+                HTMLTextAreaElementCast::to_layout_js(self.get_jsmanaged());
             if let Some(area) = area {
-                return area.get_value_for_layout();
+                return vec![ContentItem::String(area.get_value_for_layout())];
             }
 
             panic!("not text!")
@@ -661,16 +670,10 @@ impl<'le> TElementAttributes for LayoutElement<'le> {
     }
 }
 
-fn get_content(content_list: &content::T) -> String {
+fn get_content(content_list: &content::T) -> Vec<ContentItem> {
     match *content_list {
-        content::T::Content(ref value) => {
-            let iter = &mut value.clone().into_iter().peekable();
-            match iter.next() {
-                Some(content::ContentItem::StringContent(content)) => content,
-                _ => "".to_owned(),
-            }
-        }
-        _ => "".to_owned(),
+        content::T::Content(ref value) if !value.is_empty() => (*value).clone(),
+        _ => vec![],
     }
 }
 
@@ -762,7 +765,7 @@ impl<'ln> TLayoutNode for ThreadSafeLayoutNode<'ln> {
         }
     }
 
-    fn text(&self) -> String {
+    fn text_content(&self) -> Vec<ContentItem> {
         if self.pseudo != PseudoElementType::Normal {
             let layout_data_ref = self.borrow_layout_data();
             let node_layout_data_wrapper = layout_data_ref.as_ref().unwrap();
@@ -775,7 +778,7 @@ impl<'ln> TLayoutNode for ThreadSafeLayoutNode<'ln> {
                 return get_content(&after_style.get_box().content)
             }
         }
-        self.node.text()
+        self.node.text_content()
     }
 }
 
diff --git a/components/script/dom/webidls/CSSStyleDeclaration.webidl b/components/script/dom/webidls/CSSStyleDeclaration.webidl
index 46ca8424b70..bde48aaaff3 100644
--- a/components/script/dom/webidls/CSSStyleDeclaration.webidl
+++ b/components/script/dom/webidls/CSSStyleDeclaration.webidl
@@ -103,6 +103,11 @@ partial interface CSSStyleDeclaration {
   [TreatNullAs=EmptyString] attribute DOMString listStyleType;
   [TreatNullAs=EmptyString] attribute DOMString listStyleImage;
 
+  [TreatNullAs=EmptyString] attribute DOMString quotes;
+
+  [TreatNullAs=EmptyString] attribute DOMString counterIncrement;
+  [TreatNullAs=EmptyString] attribute DOMString counterReset;
+
   [TreatNullAs=EmptyString] attribute DOMString overflow;
   [TreatNullAs=EmptyString] attribute DOMString overflowX;
   [TreatNullAs=EmptyString] attribute DOMString overflowY;
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 315c0ce897e..5363ee2a931 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -763,7 +763,7 @@ dependencies = [
 [[package]]
 name = "selectors"
 version = "0.1.0"
-source = "git+https://github.com/servo/rust-selectors#1e5bbf16eee3adeec1e911c7eaa8f2be02cd4c67"
+source = "git+https://github.com/servo/rust-selectors#2a492d522ef596a05c3677bb74bf8a5b73d01855"
 dependencies = [
  "bitflags 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.2.0 (git+https://github.com/servo/rust-cssparser)",
diff --git a/components/style/properties.mako.rs b/components/style/properties.mako.rs
index 5e57d9a68ad..7d3b58916e6 100644
--- a/components/style/properties.mako.rs
+++ b/components/style/properties.mako.rs
@@ -759,86 +759,166 @@ pub mod longhands {
     ${switch_to_style_struct("Box")}
 
     <%self:longhand name="content">
-            pub use self::computed_value::T as SpecifiedValue;
-            pub use self::computed_value::ContentItem;
-            use cssparser::Token;
-            use values::computed::ComputedValueAsSpecified;
+        use cssparser::Token;
+        use std::ascii::AsciiExt;
+        use values::computed::ComputedValueAsSpecified;
 
-            impl ComputedValueAsSpecified for SpecifiedValue {}
+        use super::list_style_type;
 
-            pub mod computed_value {
-                use std::borrow::IntoCow;
-                use cssparser::{ToCss, Token};
-                use text_writer::{self, TextWriter};
+        pub use self::computed_value::T as SpecifiedValue;
+        pub use self::computed_value::ContentItem;
 
-                #[derive(PartialEq, Eq, Clone)]
-                pub enum ContentItem {
-                    StringContent(String),
-                }
+        impl ComputedValueAsSpecified for SpecifiedValue {}
 
-                impl ToCss for ContentItem {
-                    fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
-                        match self {
-                            &ContentItem::StringContent(ref s) => {
-                                Token::QuotedString((&**s).into_cow()).to_css(dest)
-                            }
+        pub mod computed_value {
+            use super::super::list_style_type;
+
+            use cssparser::{self, ToCss};
+            use text_writer::{self, TextWriter};
+
+            #[derive(PartialEq, Eq, Clone)]
+            pub enum ContentItem {
+                /// Literal string content.
+                String(String),
+                /// `counter(name, style)`.
+                Counter(String, list_style_type::computed_value::T),
+                /// `counters(name, separator, style)`.
+                Counters(String, String, list_style_type::computed_value::T),
+                /// `open-quote`.
+                OpenQuote,
+                /// `close-quote`.
+                CloseQuote,
+                /// `no-open-quote`.
+                NoOpenQuote,
+                /// `no-close-quote`.
+                NoCloseQuote,
+            }
+
+            impl ToCss for ContentItem {
+                fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
+                    match self {
+                        &ContentItem::String(ref s) => {
+                            cssparser::serialize_string(&**s, dest)
                         }
+                        &ContentItem::Counter(ref s, ref list_style_type) => {
+                            try!(dest.write_str("counter("));
+                            try!(cssparser::serialize_identifier(&**s, dest));
+                            try!(dest.write_str(", "));
+                            try!(list_style_type.to_css(dest));
+                            dest.write_str(")")
+                        }
+                        &ContentItem::Counters(ref s, ref separator, ref list_style_type) => {
+                            try!(dest.write_str("counter("));
+                            try!(cssparser::serialize_identifier(&**s, dest));
+                            try!(dest.write_str(", "));
+                            try!(cssparser::serialize_string(&**separator, dest));
+                            try!(dest.write_str(", "));
+                            try!(list_style_type.to_css(dest));
+                            dest.write_str(")")
+                        }
+                        &ContentItem::OpenQuote => dest.write_str("open-quote"),
+                        &ContentItem::CloseQuote => dest.write_str("close-quote"),
+                        &ContentItem::NoOpenQuote => dest.write_str("no-open-quote"),
+                        &ContentItem::NoCloseQuote => dest.write_str("no-close-quote"),
                     }
                 }
+            }
 
-                #[allow(non_camel_case_types)]
-                #[derive(PartialEq, Eq, Clone)]
-                pub enum T {
-                    normal,
-                    none,
-                    Content(Vec<ContentItem>),
-                }
-
-                impl ToCss for T {
-                    fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
-                        match self {
-                            &T::normal => dest.write_str("normal"),
-                            &T::none => dest.write_str("none"),
-                            &T::Content(ref content) => {
-                                let mut iter = content.iter();
-                                try!(iter.next().unwrap().to_css(dest));
-                                for c in iter {
-                                    try!(c.to_css(dest));
-                                }
-                                Ok(())
+            #[allow(non_camel_case_types)]
+            #[derive(PartialEq, Eq, Clone)]
+            pub enum T {
+                normal,
+                none,
+                Content(Vec<ContentItem>),
+            }
+
+            impl ToCss for T {
+                fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
+                    match self {
+                        &T::normal => dest.write_str("normal"),
+                        &T::none => dest.write_str("none"),
+                        &T::Content(ref content) => {
+                            let mut iter = content.iter();
+                            try!(iter.next().unwrap().to_css(dest));
+                            for c in iter {
+                                try!(dest.write_str(" "));
+                                try!(c.to_css(dest));
                             }
+                            Ok(())
                         }
                     }
                 }
             }
-            #[inline]
-            pub fn get_initial_value() -> computed_value::T  {
-                computed_value::T::normal
-            }
+        }
+        #[inline]
+        pub fn get_initial_value() -> computed_value::T  {
+            computed_value::T::normal
+        }
 
-            // normal | none | [ <string> ]+
-            // TODO: <uri>, <counter>, attr(<identifier>), open-quote, close-quote, no-open-quote, no-close-quote
-            pub fn parse(_context: &ParserContext, input: &mut Parser)
-                         -> Result<SpecifiedValue, ()> {
-                if input.try(|input| input.expect_ident_matching("normal")).is_ok() {
-                    return Ok(SpecifiedValue::normal)
-                }
-                if input.try(|input| input.expect_ident_matching("none")).is_ok() {
-                    return Ok(SpecifiedValue::none)
-                }
-                let mut content = vec![];
-                loop {
-                    match input.next() {
-                        Ok(Token::QuotedString(value)) => {
-                            content.push(ContentItem::StringContent(value.into_owned()))
-                        }
-                        Err(()) if !content.is_empty() => {
-                            return Ok(SpecifiedValue::Content(content))
+        pub fn counter_name_is_illegal(name: &str) -> bool {
+            name.eq_ignore_ascii_case("none") || name.eq_ignore_ascii_case("inherit") ||
+                name.eq_ignore_ascii_case("initial")
+        }
+
+        // normal | none | [ <string> | <counter> | open-quote | close-quote | no-open-quote |
+        // no-close-quote ]+
+        // TODO: <uri>, attr(<identifier>)
+        pub fn parse(context: &ParserContext, input: &mut Parser)
+                     -> Result<SpecifiedValue, ()> {
+            if input.try(|input| input.expect_ident_matching("normal")).is_ok() {
+                return Ok(SpecifiedValue::normal)
+            }
+            if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+                return Ok(SpecifiedValue::none)
+            }
+            let mut content = vec![];
+            loop {
+                match input.next() {
+                    Ok(Token::QuotedString(value)) => {
+                        content.push(ContentItem::String(value.into_owned()))
+                    }
+                    Ok(Token::Function(name)) => {
+                        content.push(try!(match_ignore_ascii_case! { name,
+                            "counter" => input.parse_nested_block(|input| {
+                                let name = try!(input.expect_ident()).into_owned();
+                                let style = input.try(|input| {
+                                    try!(input.expect_comma());
+                                    list_style_type::parse(context, input)
+                                }).unwrap_or(list_style_type::computed_value::T::decimal);
+                                Ok(ContentItem::Counter(name, style))
+                            }),
+                            "counters" => input.parse_nested_block(|input| {
+                                let name = try!(input.expect_ident()).into_owned();
+                                try!(input.expect_comma());
+                                let separator = try!(input.expect_string()).into_owned();
+                                let style = input.try(|input| {
+                                    try!(input.expect_comma());
+                                    list_style_type::parse(context, input)
+                                }).unwrap_or(list_style_type::computed_value::T::decimal);
+                                Ok(ContentItem::Counters(name, separator, style))
+                            })
+                            _ => return Err(())
+                        }));
+                    }
+                    Ok(Token::Ident(ident)) => {
+                        match_ignore_ascii_case! { ident,
+                            "open-quote" => content.push(ContentItem::OpenQuote),
+                            "close-quote" => content.push(ContentItem::CloseQuote),
+                            "no-open-quote" => content.push(ContentItem::NoOpenQuote),
+                            "no-close-quote" => content.push(ContentItem::NoCloseQuote)
+                            _ => return Err(())
                         }
-                        _ => return Err(())
                     }
+                    Err(_) => break,
+                    _ => return Err(())
                 }
             }
+            if !content.is_empty() {
+                Ok(SpecifiedValue::Content(content))
+            } else {
+                Err(())
+            }
+        }
     </%self:longhand>
 
     ${new_style_struct("List", is_inherited=True)}
@@ -847,14 +927,16 @@ pub mod longhands {
 
     // TODO(pcwalton): Implement the full set of counter styles per CSS-COUNTER-STYLES [1] 6.1:
     //
-    //     decimal, decimal-leading-zero, arabic-indic, armenian, upper-armenian, lower-armenian,
-    //     bengali, cambodian, khmer, cjk-decimal, devanagiri, georgian, gujarati, gurmukhi,
-    //     hebrew, kannada, lao, malayalam, mongolian, myanmar, oriya, persian, lower-roman,
-    //     upper-roman, telugu, thai, tibetan
+    //     decimal-leading-zero, armenian, upper-armenian, lower-armenian, georgian, lower-roman,
+    //     upper-roman
     //
     // [1]: http://dev.w3.org/csswg/css-counter-styles/
-    ${single_keyword("list-style-type",
-                     "disc none circle square disclosure-open disclosure-closed")}
+    ${single_keyword("list-style-type", """
+        disc none circle square decimal arabic-indic bengali cambodian cjk-decimal devanagari
+        gujarati gurmukhi kannada khmer lao malayalam mongolian myanmar oriya persian telugu thai
+        tibetan lower-alpha upper-alpha cjk-earthly-branch cjk-heavenly-stem lower-greek hiragana
+        hiragana-iroha katakana katakana-iroha disclosure-open disclosure-closed
+    """)}
 
     <%self:longhand name="list-style-image">
         use std::borrow::IntoCow;
@@ -910,6 +992,143 @@ pub mod longhands {
         }
     </%self:longhand>
 
+    <%self:longhand name="quotes">
+        use text_writer::{self, TextWriter};
+        use values::computed::ComputedValueAsSpecified;
+
+        use cssparser::{ToCss, Token};
+        use std::borrow::IntoCow;
+
+        pub use self::computed_value::T as SpecifiedValue;
+
+        pub mod computed_value {
+            #[derive(Clone, PartialEq)]
+            pub struct T(pub Vec<(String,String)>);
+        }
+
+        impl ComputedValueAsSpecified for SpecifiedValue {}
+
+        impl ToCss for SpecifiedValue {
+            fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
+                let mut first = true;
+                for pair in self.0.iter() {
+                    if !first {
+                        try!(dest.write_str(" "));
+                    }
+                    first = false;
+                    try!(Token::QuotedString(pair.0.as_slice().into_cow()).to_css(dest));
+                    try!(dest.write_str(" "));
+                    try!(Token::QuotedString(pair.1.as_slice().into_cow()).to_css(dest));
+                }
+                Ok(())
+            }
+        }
+
+        #[inline]
+        pub fn get_initial_value() -> computed_value::T {
+            computed_value::T(vec![
+                ("\u{201c}".to_string(), "\u{201d}".to_string()),
+                ("\u{2018}".to_string(), "\u{2019}".to_string()),
+            ])
+        }
+
+        pub fn parse(_: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue,()> {
+            if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+                return Ok(SpecifiedValue(Vec::new()))
+            }
+
+            let mut quotes = Vec::new();
+            loop {
+                let first = match input.next() {
+                    Ok(Token::QuotedString(value)) => value.into_owned(),
+                    Ok(_) => return Err(()),
+                    Err(()) => break,
+                };
+                let second = match input.next() {
+                    Ok(Token::QuotedString(value)) => value.into_owned(),
+                    _ => return Err(()),
+                };
+                quotes.push((first, second))
+            }
+            if !quotes.is_empty() {
+                Ok(SpecifiedValue(quotes))
+            } else {
+                Err(())
+            }
+        }
+    </%self:longhand>
+
+    ${new_style_struct("Counters", is_inherited=False)}
+
+    <%self:longhand name="counter-increment">
+        use super::content;
+        use text_writer::{self, TextWriter};
+        use values::computed::ComputedValueAsSpecified;
+
+        use cssparser::{ToCss, Token};
+        use std::borrow::{IntoCow, ToOwned};
+
+        pub use self::computed_value::T as SpecifiedValue;
+
+        pub mod computed_value {
+            #[derive(Clone, PartialEq)]
+            pub struct T(pub Vec<(String,i32)>);
+        }
+
+        #[inline]
+        pub fn get_initial_value() -> computed_value::T {
+            computed_value::T(Vec::new())
+        }
+
+        impl ComputedValueAsSpecified for SpecifiedValue {}
+
+        impl ToCss for SpecifiedValue {
+            fn to_css<W>(&self, dest: &mut W) -> text_writer::Result where W: TextWriter {
+                let mut first = true;
+                for pair in self.0.iter() {
+                    if !first {
+                        try!(dest.write_str(" "));
+                    }
+                    first = false;
+                    try!(Token::QuotedString(pair.0.as_slice().into_cow()).to_css(dest));
+                    try!(dest.write_str(format!(" {}", pair.1).as_slice()));
+                }
+                Ok(())
+            }
+        }
+
+        pub fn parse(_: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue,()> {
+            if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+                return Ok(SpecifiedValue(Vec::new()))
+            }
+
+            let mut counters = Vec::new();
+            loop {
+                let counter_name = match input.next() {
+                    Ok(Token::Ident(ident)) => (*ident).to_owned(),
+                    Ok(_) => return Err(()),
+                    Err(_) => break,
+                };
+                if content::counter_name_is_illegal(counter_name.as_slice()) {
+                    return Err(())
+                }
+                let counter_delta = input.try(|input| input.expect_integer()).unwrap_or(1) as i32;
+                counters.push((counter_name, counter_delta))
+            }
+
+            if !counters.is_empty() {
+                Ok(SpecifiedValue(counters))
+            } else {
+                Err(())
+            }
+        }
+    </%self:longhand>
+
+    <%self:longhand name="counter-reset">
+        pub use super::counter_increment::{SpecifiedValue, computed_value, get_initial_value};
+        pub use super::counter_increment::{parse};
+    </%self:longhand>
+
     // CSS 2.1, Section 13 - Paged media
 
     // CSS 2.1, Section 14 - Colors and Backgrounds
diff --git a/components/util/time.rs b/components/util/time.rs
index 46de5abbceb..c9cf32c0617 100644
--- a/components/util/time.rs
+++ b/components/util/time.rs
@@ -81,6 +81,7 @@ pub enum TimeProfilerCategory {
     LayoutSelectorMatch,
     LayoutTreeBuilder,
     LayoutDamagePropagate,
+    LayoutGeneratedContent,
     LayoutMain,
     LayoutParallelWarmup,
     LayoutShaping,
@@ -99,6 +100,7 @@ impl Formatable for TimeProfilerCategory {
             TimeProfilerCategory::LayoutStyleRecalc |
             TimeProfilerCategory::LayoutRestyleDamagePropagation |
             TimeProfilerCategory::LayoutNonIncrementalReset |
+            TimeProfilerCategory::LayoutGeneratedContent |
             TimeProfilerCategory::LayoutMain |
             TimeProfilerCategory::LayoutDispListBuild |
             TimeProfilerCategory::LayoutShaping |
@@ -119,6 +121,7 @@ impl Formatable for TimeProfilerCategory {
             TimeProfilerCategory::LayoutSelectorMatch => "Selector Matching",
             TimeProfilerCategory::LayoutTreeBuilder => "Tree Building",
             TimeProfilerCategory::LayoutDamagePropagate => "Damage Propagation",
+            TimeProfilerCategory::LayoutGeneratedContent => "Generated Content Resolution",
             TimeProfilerCategory::LayoutMain => "Primary Layout Pass",
             TimeProfilerCategory::LayoutParallelWarmup => "Parallel Warmup",
             TimeProfilerCategory::LayoutShaping => "Shaping",
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 8ae649f776f..8504a68c52c 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -771,7 +771,7 @@ dependencies = [
 [[package]]
 name = "selectors"
 version = "0.1.0"
-source = "git+https://github.com/servo/rust-selectors#1e5bbf16eee3adeec1e911c7eaa8f2be02cd4c67"
+source = "git+https://github.com/servo/rust-selectors#2a492d522ef596a05c3677bb74bf8a5b73d01855"
 dependencies = [
  "bitflags 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.2.0 (git+https://github.com/servo/rust-cssparser)",
diff --git a/ports/gonk/Cargo.lock b/ports/gonk/Cargo.lock
index 12dd2979ee7..981037eb606 100644
--- a/ports/gonk/Cargo.lock
+++ b/ports/gonk/Cargo.lock
@@ -682,7 +682,7 @@ dependencies = [
 [[package]]
 name = "selectors"
 version = "0.1.0"
-source = "git+https://github.com/servo/rust-selectors#1e5bbf16eee3adeec1e911c7eaa8f2be02cd4c67"
+source = "git+https://github.com/servo/rust-selectors#2a492d522ef596a05c3677bb74bf8a5b73d01855"
 dependencies = [
  "bitflags 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.2.0 (git+https://github.com/servo/rust-cssparser)",
diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index d26f5656428..4d26321575e 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -65,6 +65,8 @@ flaky_cpu == append_style_a.html append_style_b.html
 == case-insensitive-font-family.html case-insensitive-font-family-ref.html
 == clear_generated_content_table_a.html clear_generated_content_table_ref.html
 == clip_a.html clip_ref.html
+== counters_nested_a.html counters_nested_ref.html
+== counters_simple_a.html counters_simple_ref.html
 == data_img_a.html data_img_b.html
 == empty_cells_a.html empty_cells_ref.html
 == filter_opacity_a.html filter_opacity_ref.html
@@ -177,6 +179,9 @@ flaky_cpu == linebreak_simple_a.html linebreak_simple_b.html
 == nth_last_of_type_pseudo_a.html nth_last_of_type_pseudo_b.html
 == nth_of_type_pseudo_a.html nth_of_type_pseudo_b.html
 == object_element_a.html object_element_b.html
+== ol_japanese_iroha_a.html ol_japanese_iroha_ref.html
+!= ol_japanese_iroha_bullet_styles.html ol_japanese_iroha_ref.html
+== ol_simple_a.html ol_simple_ref.html
 == only_child_pseudo_a.html only_child_pseudo_b.html
 == only_of_type_pseudo_a.html only_of_type_pseudo_b.html
 == opacity_simple_a.html opacity_simple_ref.html
@@ -220,6 +225,7 @@ experimental != overconstrained_block.html overconstrained_block_ref.html
 == pre_ignorable_whitespace_a.html pre_ignorable_whitespace_ref.html
 == pseudo_element_a.html pseudo_element_b.html
 == pseudo_inherit.html pseudo_inherit_ref.html
+== quotes_simple_a.html quotes_simple_ref.html
 == root_height_a.html root_height_b.html
 == root_margin_collapse_a.html root_margin_collapse_b.html
 == root_pseudo_a.html root_pseudo_b.html
diff --git a/tests/ref/counters_nested_a.html b/tests/ref/counters_nested_a.html
new file mode 100644
index 00000000000..39baa0ac16b
--- /dev/null
+++ b/tests/ref/counters_nested_a.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that `counters` works with nested counters. -->
+<style>
+section {
+    counter-reset: section 0;
+}
+h1, h2, h3 {
+    counter-increment: section 1;
+    font-size: 24px;
+}
+h1:before, h2:before, h3:before {
+    content: counters(section, ".") ". ";
+}
+</style>
+</head>
+<body>
+<section>
+    <h1>Foo</h1>
+    <section>
+        <h2>Boo</h2>
+        <h2>Quux</h2>
+        <section>
+            <h3>Blah</h3>
+        </section>
+    </section>
+    <h1>Bar</h1>
+    <section></section>
+    <h2>Boo</h2>
+    <h2>Quux</h2>
+    <h1>Baz</h1>
+</section>
+</body>
+</html>
+
diff --git a/tests/ref/counters_nested_ref.html b/tests/ref/counters_nested_ref.html
new file mode 100644
index 00000000000..b42f6509c83
--- /dev/null
+++ b/tests/ref/counters_nested_ref.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that `counters` works with nested counters. -->
+<style>
+h1, h2, h3 {
+    font-size: 24px;
+}
+</style>
+</head>
+<body>
+<section>
+    <h1>1. Foo</h1>
+    <section>
+        <h2>1.1. Boo</h2>
+        <h2>1.2. Quux</h2>
+        <section>
+            <h3>1.2.1. Blah</h3>
+        </section>
+    </section>
+    <h1>1.3. Bar</h1>
+    <section></section>
+    <h2>1.1. Boo</h2>
+    <h2>1.2. Quux</h2>
+    <h1>1.3. Baz</h1>
+</section>
+</body>
+</html>
+
diff --git a/tests/ref/counters_simple_a.html b/tests/ref/counters_simple_a.html
new file mode 100644
index 00000000000..e8534e3da17
--- /dev/null
+++ b/tests/ref/counters_simple_a.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that `counter` works. -->
+<style>
+h1, h2, h3 {
+    font-size: 24px;
+}
+h1 {
+    counter-increment: section 1;
+    counter-reset: subsection 0;
+}
+h1:before {
+    content: counter(section) ". ";
+}
+h2 {
+    counter-increment: subsection 1;
+    counter-reset: subsubsection 0;
+}
+h2:before {
+    content: counter(section) "." counter(subsection) ". ";
+}
+h3 {
+    counter-increment: subsubsection;
+}
+h3:before {
+    content: counter(section) "." counter(subsection) "." counter(subsubsection) ". ";
+}
+</style>
+</head>
+<body>
+<h1>Foo</h1>
+    <h2>Boo</h2>
+    <h2>Quux</h2>
+        <h3>Blah</h3>
+<h1>Bar</h1>
+    <h2>Boo</h2>
+    <h2>Quux</h2>
+<h1>Baz</h1>
+</body>
+</html>
+
diff --git a/tests/ref/counters_simple_ref.html b/tests/ref/counters_simple_ref.html
new file mode 100644
index 00000000000..b1adc96fb26
--- /dev/null
+++ b/tests/ref/counters_simple_ref.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that `counter` works. -->
+<style>
+h1, h2, h3 {
+    font-size: 24px;
+}
+</style>
+</head>
+<body>
+<h1>1. Foo</h1>
+    <h2>1.1. Boo</h2>
+    <h2>1.2. Quux</h2>
+        <h3>1.2.1. Blah</h3>
+<h1>2. Bar</h1>
+    <h2>2.1. Boo</h2>
+    <h2>2.2. Quux</h2>
+<h1>3. Baz</h1>
+</body>
+</html>
+
diff --git a/tests/ref/ol_japanese_iroha_a.html b/tests/ref/ol_japanese_iroha_a.html
new file mode 100644
index 00000000000..1a7d2315b85
--- /dev/null
+++ b/tests/ref/ol_japanese_iroha_a.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that Japanese iroha ordering works in list items. -->
+<style>
+body {
+    font-family: "Hiragino Maru Gothic Pro", TakaoPGothic, sans-serif;
+}
+ol {
+    list-style-position: inside;
+    list-style-type: hiragana-iroha;
+}
+li {
+}
+</style>
+</head>
+<body>
+<ol>
+    <li>Gryffindor</li>
+    <li>Hufflepuff</li>
+    <li>Ravenclaw</li>
+    <li>Slytherin</li>
+</ol>
+</body>
+</html>
+
+
diff --git a/tests/ref/ol_japanese_iroha_bullet_styles.html b/tests/ref/ol_japanese_iroha_bullet_styles.html
new file mode 100644
index 00000000000..050f36666ed
--- /dev/null
+++ b/tests/ref/ol_japanese_iroha_bullet_styles.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Ensures that U+3044, U+308D, U+306F, and U+306B are all supported in the current font. -->
+<style>
+body {
+    font-family: "Hiragino Maru Gothic Pro", TakaoPGothic, sans-serif;
+}
+ol {
+    list-style-position: inside;
+    list-style-type: none;
+}
+</style>
+</head>
+<body>
+<ol>
+    <li>&#x3044;. Gryffindor</li>
+    <li>&#x3044;. Hufflepuff</li>
+    <li>&#x3044;. Ravenclaw</li>
+    <li>&#x3044;. Slytherin</li>
+</ol>
+</body>
+</html>
+
+
diff --git a/tests/ref/ol_japanese_iroha_ref.html b/tests/ref/ol_japanese_iroha_ref.html
new file mode 100644
index 00000000000..a32a32a2591
--- /dev/null
+++ b/tests/ref/ol_japanese_iroha_ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that Japanese iroha ordering works in list items.
+
+     FIXME(pcwalton): This shouldn't have a "." after the kana. -->
+<style>
+body {
+    font-family: "Hiragino Maru Gothic Pro", TakaoPGothic, sans-serif;
+}
+ol {
+    list-style-position: inside;
+    list-style-type: none;
+}
+</style>
+</head>
+<body>
+<ol>
+    <li>&#x3044;. Gryffindor</li>
+    <li>&#x308d;. Hufflepuff</li>
+    <li>&#x306f;. Ravenclaw</li>
+    <li>&#x306b;. Slytherin</li>
+</ol>
+</body>
+</html>
+
+
diff --git a/tests/ref/ol_simple_a.html b/tests/ref/ol_simple_a.html
new file mode 100644
index 00000000000..e63c00c4ceb
--- /dev/null
+++ b/tests/ref/ol_simple_a.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<style>
+li {
+    list-style-type: decimal;
+    list-style-position: inside;
+}
+</style>
+</head>
+<body>
+<ol>
+    <li>Foo</li>
+    <li>Bar</li>
+    <li>Baz</li>
+</ol>
+</body>
+</html>
+
diff --git a/tests/ref/ol_simple_ref.html b/tests/ref/ol_simple_ref.html
new file mode 100644
index 00000000000..d3411bb2e6d
--- /dev/null
+++ b/tests/ref/ol_simple_ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<style>
+li {
+    list-style-type: none;
+    list-style-position: inside;
+}
+</style>
+</head>
+<body>
+<ol>
+    <li>1. Foo</li>
+    <li>2. Bar</li>
+    <li>3. Baz</li>
+</ol>
+</body>
+</html>
+
diff --git a/tests/ref/quotes_simple_a.html b/tests/ref/quotes_simple_a.html
new file mode 100644
index 00000000000..257be1276e0
--- /dev/null
+++ b/tests/ref/quotes_simple_a.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that the initial value of `quotes` works. -->
+</head>
+<body>
+I remember when I first read <q>Hagrid said, <q>You're a wizard, Harry!</q></q>
+</body>
+</html>
+
diff --git a/tests/ref/quotes_simple_ref.html b/tests/ref/quotes_simple_ref.html
new file mode 100644
index 00000000000..b378efaa4ab
--- /dev/null
+++ b/tests/ref/quotes_simple_ref.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+<head>
+<!-- Tests that the initial value of `quotes` works. -->
+</head>
+<body>
+I remember when I first read &#x201c;Hagrid said, &#x2018;You're a wizard, Harry!&#x2019;&#x201d;
+</body>
+</html>
+
+