style: Fix servo build.

This also fixes a bunch of calc handling issues and such.

Also remove tests that no longer compile and are covered by WPT.

17 files changed, 197 insertions, 434 deletions

diff --git a/components/layout/block.rs b/components/layout/block.rs
index 823d5226ea1..5cf6597654f 100644
--- a/components/layout/block.rs
+++ b/components/layout/block.rs
@@ -66,8 +66,7 @@ use style::context::SharedStyleContext;
 use style::logical_geometry::{LogicalMargin, LogicalPoint, LogicalRect, LogicalSize, WritingMode};
 use style::properties::ComputedValues;
 use style::servo::restyle_damage::ServoRestyleDamage;
-use style::values::computed::LengthOrPercentageOrAuto;
-use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrNone};
+use style::values::computed::{LengthOrPercentageOrAuto, LengthOrPercentageOrNone};
 
 /// Information specific to floated blocks.
 #[derive(Clone, Serialize)]
@@ -418,42 +417,23 @@ impl CandidateBSizeIterator {
         // If that is not determined yet by the time we need to resolve
         // `min-height` and `max-height`, percentage values are ignored.
 
-        let block_size = match (
-            fragment.style.content_block_size(),
-            block_container_block_size,
-        ) {
-            (LengthOrPercentageOrAuto::Percentage(percent), Some(block_container_block_size)) => {
-                MaybeAuto::Specified(block_container_block_size.scale_by(percent.0))
-            },
-            (LengthOrPercentageOrAuto::Calc(calc), _) => {
-                MaybeAuto::from_option(calc.to_used_value(block_container_block_size))
-            },
-            (LengthOrPercentageOrAuto::Percentage(_), None) |
-            (LengthOrPercentageOrAuto::Auto, _) => MaybeAuto::Auto,
-            (LengthOrPercentageOrAuto::Length(length), _) => MaybeAuto::Specified(Au::from(length)),
-        };
-        let max_block_size = match (fragment.style.max_block_size(), block_container_block_size) {
-            (LengthOrPercentageOrNone::Percentage(percent), Some(block_container_block_size)) => {
-                Some(block_container_block_size.scale_by(percent.0))
-            },
-            (LengthOrPercentageOrNone::Calc(calc), _) => {
-                calc.to_used_value(block_container_block_size)
+        let block_size = match fragment.style.content_block_size() {
+            LengthOrPercentageOrAuto::Auto => MaybeAuto::Auto,
+            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                MaybeAuto::from_option(lp.maybe_to_used_value(block_container_block_size))
             },
-            (LengthOrPercentageOrNone::Percentage(_), None) |
-            (LengthOrPercentageOrNone::None, _) => None,
-            (LengthOrPercentageOrNone::Length(length), _) => Some(Au::from(length)),
         };
-        let min_block_size = match (fragment.style.min_block_size(), block_container_block_size) {
-            (LengthOrPercentage::Percentage(percent), Some(block_container_block_size)) => {
-                block_container_block_size.scale_by(percent.0)
+
+        let max_block_size = match fragment.style.max_block_size() {
+            LengthOrPercentageOrNone::None => None,
+            LengthOrPercentageOrNone::LengthOrPercentage(ref lp) => {
+                lp.maybe_to_used_value(block_container_block_size)
             },
-            (LengthOrPercentage::Calc(calc), _) => calc
-                .to_used_value(block_container_block_size)
-                .unwrap_or(Au(0)),
-            (LengthOrPercentage::Percentage(_), None) => Au(0),
-            (LengthOrPercentage::Length(length), _) => Au::from(length),
         };
 
+        let min_block_size =
+            fragment.style.min_block_size().maybe_to_used_value(block_container_block_size).unwrap_or(Au(0));
+
         // If the style includes `box-sizing: border-box`, subtract the border and padding.
         let adjustment_for_box_sizing = match fragment.style.get_position().box_sizing {
             BoxSizing::BorderBox => fragment.border_padding.block_start_end(),
@@ -1415,15 +1395,9 @@ impl BlockFlow {
     pub fn explicit_block_size(&self, containing_block_size: Option<Au>) -> Option<Au> {
         let content_block_size = self.fragment.style().content_block_size();
 
-        match (content_block_size, containing_block_size) {
-            (LengthOrPercentageOrAuto::Calc(calc), _) => calc.to_used_value(containing_block_size),
-            (LengthOrPercentageOrAuto::Length(length), _) => Some(Au::from(length)),
-            (LengthOrPercentageOrAuto::Percentage(percent), Some(container_size)) => {
-                Some(container_size.scale_by(percent.0))
-            },
-            (LengthOrPercentageOrAuto::Percentage(_), None) |
-            (LengthOrPercentageOrAuto::Auto, None) => None,
-            (LengthOrPercentageOrAuto::Auto, Some(container_size)) => {
+        match content_block_size {
+            LengthOrPercentageOrAuto::Auto => {
+                let container_size = containing_block_size?;
                 let (block_start, block_end) = {
                     let position = self.fragment.style().logical_position();
                     (
@@ -1454,10 +1428,12 @@ impl BlockFlow {
                         let sum = block_start + block_end + margin_block_start + margin_block_end;
                         Some(available_block_size - sum)
                     },
-
                     (_, _) => None,
                 }
             },
+            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                lp.maybe_to_used_value(containing_block_size)
+            },
         }
     }
 
@@ -2177,8 +2153,8 @@ impl Flow for BlockFlow {
         // If this block has a fixed width, just use that for the minimum and preferred width,
         // rather than bubbling up children inline width.
         let consult_children = match self.fragment.style().get_position().width {
-            LengthOrPercentageOrAuto::Length(_) => false,
-            _ => true,
+            LengthOrPercentageOrAuto::Auto => true,
+            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => lp.maybe_to_used_value(None).is_none(),
         };
         self.bubble_inline_sizes_for_block(consult_children);
         self.fragment
diff --git a/components/layout/display_list/gradient.rs b/components/layout/display_list/gradient.rs
index 6cdee3d6df8..f7fc834e8d8 100644
--- a/components/layout/display_list/gradient.rs
+++ b/components/layout/display_list/gradient.rs
@@ -107,14 +107,14 @@ fn convert_gradient_stops(
     {
         let first = stop_items.first_mut().unwrap();
         if first.position.is_none() {
-            first.position = Some(LengthOrPercentage::Percentage(Percentage(0.0)));
+            first.position = Some(LengthOrPercentage::new_percent(Percentage(0.)));
         }
     }
     // If the last color stop does not have a position, set its position to 100%.
     {
         let last = stop_items.last_mut().unwrap();
         if last.position.is_none() {
-            last.position = Some(LengthOrPercentage::Percentage(Percentage(1.0)));
+            last.position = Some(LengthOrPercentage::new_percent(Percentage(1.0)));
         }
     }
 
@@ -214,13 +214,7 @@ fn position_to_offset(position: LengthOrPercentage, total_length: Au) -> f32 {
     if total_length == Au(0) {
         return 0.0;
     }
-    match position {
-        LengthOrPercentage::Length(l) => l.to_i32_au() as f32 / total_length.0 as f32,
-        LengthOrPercentage::Percentage(percentage) => percentage.0 as f32,
-        LengthOrPercentage::Calc(calc) => {
-            calc.to_used_value(Some(total_length)).unwrap().0 as f32 / total_length.0 as f32
-        },
-    }
+    position.to_used_value(total_length).0 as f32 / total_length.0 as f32
 }
 
 pub fn linear(
diff --git a/components/layout/flex.rs b/components/layout/flex.rs
index 1848cdf2e81..fbd01c14dca 100644
--- a/components/layout/flex.rs
+++ b/components/layout/flex.rs
@@ -12,7 +12,7 @@ use crate::floats::FloatKind;
 use crate::flow::{Flow, FlowClass, FlowFlags, GetBaseFlow, ImmutableFlowUtils, OpaqueFlow};
 use crate::fragment::{Fragment, FragmentBorderBoxIterator, Overflow};
 use crate::layout_debug;
-use crate::model::{AdjoiningMargins, CollapsibleMargins};
+use crate::model::{self, AdjoiningMargins, CollapsibleMargins};
 use crate::model::{IntrinsicISizes, MaybeAuto, SizeConstraint};
 use crate::traversal::PreorderFlowTraversal;
 use app_units::{Au, MAX_AU};
@@ -52,18 +52,15 @@ impl AxisSize {
         max: LengthOrPercentageOrNone,
     ) -> AxisSize {
         match size {
-            LengthOrPercentageOrAuto::Length(length) => AxisSize::Definite(Au::from(length)),
-            LengthOrPercentageOrAuto::Percentage(percent) => match content_size {
-                Some(size) => AxisSize::Definite(size.scale_by(percent.0)),
-                None => AxisSize::Infinite,
-            },
-            LengthOrPercentageOrAuto::Calc(calc) => match calc.to_used_value(content_size) {
-                Some(length) => AxisSize::Definite(length),
-                None => AxisSize::Infinite,
-            },
             LengthOrPercentageOrAuto::Auto => {
                 AxisSize::MinMax(SizeConstraint::new(content_size, min, max, None))
-            },
+            }
+            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                match lp.maybe_to_used_value(content_size) {
+                    Some(length) => AxisSize::Definite(length),
+                    None => AxisSize::Infinite,
+                }
+            }
         }
     }
 }
@@ -461,10 +458,11 @@ impl FlexFlow {
     // Currently, this is the core of BlockFlow::bubble_inline_sizes() with all float logic
     // stripped out, and max replaced with union_nonbreaking_inline.
     fn inline_mode_bubble_inline_sizes(&mut self) {
-        let fixed_width = match self.block_flow.fragment.style().get_position().width {
-            LengthOrPercentageOrAuto::Length(_) => true,
-            _ => false,
-        };
+        // FIXME(emilio): This doesn't handle at all writing-modes.
+        let fixed_width = !model::style_length(
+            self.block_flow.fragment.style().get_position().width,
+            None,
+        ).is_auto();
 
         let mut computation = self.block_flow.fragment.compute_intrinsic_inline_sizes();
         if !fixed_width {
@@ -488,10 +486,10 @@ impl FlexFlow {
     // Currently, this is the core of BlockFlow::bubble_inline_sizes() with all float logic
     // stripped out.
     fn block_mode_bubble_inline_sizes(&mut self) {
-        let fixed_width = match self.block_flow.fragment.style().get_position().width {
-            LengthOrPercentageOrAuto::Length(_) => true,
-            _ => false,
-        };
+        let fixed_width = !model::style_length(
+            self.block_flow.fragment.style().get_position().width,
+            None,
+        ).is_auto();
 
         let mut computation = self.block_flow.fragment.compute_intrinsic_inline_sizes();
         if !fixed_width {
diff --git a/components/layout/floats.rs b/components/layout/floats.rs
index 5e9ee3ae886..9aa25f4e9b6 100644
--- a/components/layout/floats.rs
+++ b/components/layout/floats.rs
@@ -542,16 +542,21 @@ impl SpeculatedFloatPlacement {
         let mut float_inline_size = base_flow.intrinsic_inline_sizes.preferred_inline_size;
         if float_inline_size == Au(0) {
             if flow.is_block_like() {
-                // Hack: If the size of the float is a percentage, then there's no way we can guess
-                // at its size now. So just pick an arbitrary nonzero value (in this case, 1px) so
-                // that the layout traversal logic will know that objects later in the document
+                // Hack: If the size of the float is not fixed, then there's no
+                // way we can guess at its size now. So just pick an arbitrary
+                // nonzero value (in this case, 1px) so that the layout
+                // traversal logic will know that objects later in the document
                 // might flow around this float.
-                if let LengthOrPercentageOrAuto::Percentage(percentage) =
-                    flow.as_block().fragment.style.content_inline_size()
-                {
-                    if percentage.0 > 0.0 {
-                        float_inline_size = Au::from_px(1)
+                let inline_size =
+                    flow.as_block().fragment.style.content_inline_size();
+                let fixed = match inline_size {
+                    LengthOrPercentageOrAuto::Auto => false,
+                    LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                        lp.is_definitely_zero() || lp.maybe_to_used_value(None).is_some()
                     }
+                };
+                if !fixed {
+                    float_inline_size = Au::from_px(1)
                 }
             }
         }
diff --git a/components/layout/fragment.rs b/components/layout/fragment.rs
index 3e84a36c595..5560941aaa8 100644
--- a/components/layout/fragment.rs
+++ b/components/layout/fragment.rs
@@ -61,7 +61,7 @@ use style::selector_parser::RestyleDamage;
 use style::servo::restyle_damage::ServoRestyleDamage;
 use style::str::char_is_whitespace;
 use style::values::computed::counters::ContentItem;
-use style::values::computed::{Length, LengthOrPercentage, LengthOrPercentageOrAuto};
+use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto};
 use style::values::generics::box_::{Perspective, VerticalAlign};
 use style::values::generics::transform;
 use webrender_api::{self, LayoutTransform};
@@ -1610,33 +1610,32 @@ impl Fragment {
             SpecificFragmentInfo::Canvas(_) |
             SpecificFragmentInfo::Iframe(_) |
             SpecificFragmentInfo::Svg(_) => {
-                let mut inline_size = match self.style.content_inline_size() {
-                    LengthOrPercentageOrAuto::Auto | LengthOrPercentageOrAuto::Percentage(_) => {
-                        // We have to initialize the `border_padding` field first to make
-                        // the size constraints work properly.
-                        // TODO(stshine): Find a cleaner way to do this.
-                        let padding = self.style.logical_padding();
-                        self.border_padding.inline_start =
-                            padding.inline_start.to_used_value(Au(0));
-                        self.border_padding.inline_end = padding.inline_end.to_used_value(Au(0));
-                        self.border_padding.block_start = padding.block_start.to_used_value(Au(0));
-                        self.border_padding.block_end = padding.block_end.to_used_value(Au(0));
-                        let border = self.border_width();
-                        self.border_padding.inline_start += border.inline_start;
-                        self.border_padding.inline_end += border.inline_end;
-                        self.border_padding.block_start += border.block_start;
-                        self.border_padding.block_end += border.block_end;
-                        let (result_inline, _) = self.calculate_replaced_sizes(None, None);
-                        result_inline
-                    },
-                    LengthOrPercentageOrAuto::Length(length) => Au::from(length),
-                    LengthOrPercentageOrAuto::Calc(calc) => {
-                        // TODO(nox): This is probably wrong, because it accounts neither for
-                        // clamping (not sure if necessary here) nor percentage.
-                        Au::from(calc.unclamped_length())
-                    },
+                let inline_size = match self.style.content_inline_size() {
+                    LengthOrPercentageOrAuto::Auto => None,
+                    LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                        lp.maybe_to_used_value(None)
+                    }
                 };
 
+                let mut inline_size = inline_size.unwrap_or_else(|| {
+                    // We have to initialize the `border_padding` field first to make
+                    // the size constraints work properly.
+                    // TODO(stshine): Find a cleaner way to do this.
+                    let padding = self.style.logical_padding();
+                    self.border_padding.inline_start =
+                        padding.inline_start.to_used_value(Au(0));
+                    self.border_padding.inline_end = padding.inline_end.to_used_value(Au(0));
+                    self.border_padding.block_start = padding.block_start.to_used_value(Au(0));
+                    self.border_padding.block_end = padding.block_end.to_used_value(Au(0));
+                    let border = self.border_width();
+                    self.border_padding.inline_start += border.inline_start;
+                    self.border_padding.inline_end += border.inline_end;
+                    self.border_padding.block_start += border.block_start;
+                    self.border_padding.block_end += border.block_end;
+                    let (result_inline, _) = self.calculate_replaced_sizes(None, None);
+                    result_inline
+                });
+
                 let size_constraint = self.size_constraint(None, Direction::Inline);
                 inline_size = size_constraint.clamp(inline_size);
 
@@ -2432,16 +2431,8 @@ impl Fragment {
                             content_inline_metrics.space_below_baseline
                     }
                 },
-                VerticalAlign::Length(LengthOrPercentage::Length(length)) => {
-                    offset -= Au::from(length)
-                },
-                VerticalAlign::Length(LengthOrPercentage::Percentage(percentage)) => {
-                    offset -= minimum_line_metrics.space_needed().scale_by(percentage.0)
-                },
-                VerticalAlign::Length(LengthOrPercentage::Calc(formula)) => {
-                    offset -= formula
-                        .to_used_value(Some(minimum_line_metrics.space_needed()))
-                        .unwrap()
+                VerticalAlign::Length(ref lp) => {
+                    offset -= lp.to_used_value(minimum_line_metrics.space_needed());
                 },
             }
         }
@@ -2519,12 +2510,12 @@ impl Fragment {
                             continue;
                         }
                         if inline_context_node.style.logical_margin().inline_end !=
-                            LengthOrPercentageOrAuto::Length(Length::new(0.))
+                            LengthOrPercentageOrAuto::zero()
                         {
                             return false;
                         }
                         if inline_context_node.style.logical_padding().inline_end !=
-                            LengthOrPercentage::Length(Length::new(0.))
+                            LengthOrPercentage::zero()
                         {
                             return false;
                         }
@@ -2545,12 +2536,12 @@ impl Fragment {
                             continue;
                         }
                         if inline_context_node.style.logical_margin().inline_start !=
-                            LengthOrPercentageOrAuto::Length(Length::new(0.))
+                            LengthOrPercentageOrAuto::zero()
                         {
                             return false;
                         }
                         if inline_context_node.style.logical_padding().inline_start !=
-                            LengthOrPercentage::Length(Length::new(0.))
+                            LengthOrPercentage::zero()
                         {
                             return false;
                         }
diff --git a/components/layout/model.rs b/components/layout/model.rs
index 4db60d05a4b..a54e3a9b76e 100644
--- a/components/layout/model.rs
+++ b/components/layout/model.rs
@@ -136,26 +136,19 @@ impl MarginCollapseInfo {
                 may_collapse_through = may_collapse_through &&
                     match fragment.style().content_block_size() {
                         LengthOrPercentageOrAuto::Auto => true,
-                        LengthOrPercentageOrAuto::Length(l) => l.px() == 0.,
-                        LengthOrPercentageOrAuto::Percentage(v) => {
-                            v.0 == 0. || containing_block_size.is_none()
+                        LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                            lp.is_definitely_zero() ||
+                                lp.maybe_to_used_value(containing_block_size).is_none()
                         },
-                        LengthOrPercentageOrAuto::Calc(_) => false,
                     };
 
                 if may_collapse_through {
-                    match fragment.style().min_block_size() {
-                        LengthOrPercentage::Length(l) if l.px() == 0. => {
-                            FinalMarginState::MarginsCollapseThrough
-                        },
-                        LengthOrPercentage::Percentage(v) if v.0 == 0. => {
-                            FinalMarginState::MarginsCollapseThrough
-                        },
-                        _ => {
-                            // If the fragment has non-zero min-block-size, margins may not
-                            // collapse through it.
-                            FinalMarginState::BottomMarginCollapses
-                        },
+                    if fragment.style().min_block_size().is_definitely_zero() {
+                        FinalMarginState::MarginsCollapseThrough
+                    } else {
+                        // If the fragment has non-zero min-block-size, margins may not
+                        // collapse through it.
+                        FinalMarginState::BottomMarginCollapses
                     }
                 } else {
                     // If the fragment has an explicitly specified block-size, margins may not
@@ -445,13 +438,9 @@ impl MaybeAuto {
     pub fn from_style(length: LengthOrPercentageOrAuto, containing_length: Au) -> MaybeAuto {
         match length {
             LengthOrPercentageOrAuto::Auto => MaybeAuto::Auto,
-            LengthOrPercentageOrAuto::Percentage(percent) => {
-                MaybeAuto::Specified(containing_length.scale_by(percent.0))
+            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                MaybeAuto::Specified(lp.to_used_value(containing_length))
             },
-            LengthOrPercentageOrAuto::Calc(calc) => {
-                MaybeAuto::from_option(calc.to_used_value(Some(containing_length)))
-            },
-            LengthOrPercentageOrAuto::Length(length) => MaybeAuto::Specified(Au::from(length)),
         }
     }
 
@@ -485,6 +474,15 @@ impl MaybeAuto {
     }
 
     #[inline]
+    pub fn is_auto(&self) -> bool {
+        match *self {
+            MaybeAuto::Auto => true,
+            MaybeAuto::Specified(..) => false,
+        }
+    }
+
+
+    #[inline]
     pub fn map<F>(&self, mapper: F) -> MaybeAuto
     where
         F: FnOnce(Au) -> Au,
@@ -503,15 +501,11 @@ pub fn style_length(
     style_length: LengthOrPercentageOrAuto,
     container_size: Option<Au>,
 ) -> MaybeAuto {
-    match container_size {
-        Some(length) => MaybeAuto::from_style(style_length, length),
-        None => {
-            if let LengthOrPercentageOrAuto::Length(length) = style_length {
-                MaybeAuto::Specified(Au::from(length))
-            } else {
-                MaybeAuto::Auto
-            }
-        },
+    match style_length {
+        LengthOrPercentageOrAuto::Auto => MaybeAuto::Auto,
+        LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+            MaybeAuto::from_option(lp.maybe_to_used_value(container_size))
+        }
     }
 }
 
@@ -580,27 +574,16 @@ impl SizeConstraint {
         max_size: LengthOrPercentageOrNone,
         border: Option<Au>,
     ) -> SizeConstraint {
-        let mut min_size = match container_size {
-            Some(container_size) => min_size.to_used_value(container_size),
-            None => {
-                if let LengthOrPercentage::Length(length) = min_size {
-                    Au::from(length)
-                } else {
-                    Au(0)
-                }
-            },
-        };
+        let mut min_size =
+            min_size.maybe_to_used_value(container_size).unwrap_or(Au(0));
 
-        let mut max_size = match container_size {
-            Some(container_size) => max_size.to_used_value(container_size),
-            None => {
-                if let LengthOrPercentageOrNone::Length(length) = max_size {
-                    Some(Au::from(length))
-                } else {
-                    None
-                }
+        let mut max_size = match max_size {
+            LengthOrPercentageOrNone::None => None,
+            LengthOrPercentageOrNone::LengthOrPercentage(ref lp) => {
+                lp.maybe_to_used_value(container_size)
             },
         };
+
         // Make sure max size is not smaller than min size.
         max_size = max_size.map(|x| max(x, min_size));
 
@@ -609,10 +592,7 @@ impl SizeConstraint {
             max_size = max_size.map(|x| max(x - border, Au(0)));
         }
 
-        SizeConstraint {
-            min_size: min_size,
-            max_size: max_size,
-        }
+        SizeConstraint { min_size, max_size }
     }
 
     /// Clamp the given size by the given min size and max size constraint.
diff --git a/components/layout/multicol.rs b/components/layout/multicol.rs
index 294670f0a1e..e0234454b27 100644
--- a/components/layout/multicol.rs
+++ b/components/layout/multicol.rs
@@ -154,11 +154,22 @@ impl Flow for MulticolFlow {
             this_fragment_is_empty: true,
             available_block_size: {
                 let style = &self.block_flow.fragment.style;
-                if let LengthOrPercentageOrAuto::Length(length) = style.content_block_size() {
-                    Au::from(length)
-                } else if let LengthOrPercentageOrNone::Length(length) = style.max_block_size() {
-                    Au::from(length)
-                } else {
+                let size = match style.content_block_size() {
+                    LengthOrPercentageOrAuto::Auto => None,
+                    LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                        lp.maybe_to_used_value(None)
+                    }
+                };
+                let size = size.or_else(|| {
+                    match style.max_block_size() {
+                        LengthOrPercentageOrNone::None => None,
+                        LengthOrPercentageOrNone::LengthOrPercentage(ref lp) => {
+                            lp.maybe_to_used_value(None)
+                        }
+                    }
+                });
+
+                size.unwrap_or_else(|| {
                     // FIXME: do column balancing instead
                     // FIXME: (until column balancing) substract margins/borders/padding
                     LogicalSize::from_physical(
@@ -166,7 +177,7 @@ impl Flow for MulticolFlow {
                         ctx.shared_context().viewport_size(),
                     )
                     .block
-                }
+                })
             },
         });
 
diff --git a/components/layout/table.rs b/components/layout/table.rs
index 5f08b107b31..f492e9056ff 100644
--- a/components/layout/table.rs
+++ b/components/layout/table.rs
@@ -301,16 +301,16 @@ impl Flow for TableFlow {
                 self.column_intrinsic_inline_sizes
                     .push(ColumnIntrinsicInlineSize {
                         minimum_length: match *specified_inline_size {
-                            LengthOrPercentageOrAuto::Auto |
-                            LengthOrPercentageOrAuto::Calc(_) |
-                            LengthOrPercentageOrAuto::Percentage(_) => Au(0),
-                            LengthOrPercentageOrAuto::Length(length) => Au::from(length),
+                            LengthOrPercentageOrAuto::Auto => Au(0),
+                            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                                lp.maybe_to_used_value(None).unwrap_or(Au(0))
+                            },
                         },
                         percentage: match *specified_inline_size {
-                            LengthOrPercentageOrAuto::Auto |
-                            LengthOrPercentageOrAuto::Calc(_) |
-                            LengthOrPercentageOrAuto::Length(_) => 0.0,
-                            LengthOrPercentageOrAuto::Percentage(percentage) => percentage.0,
+                            LengthOrPercentageOrAuto::Auto => 0.0,
+                            LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                                lp.as_percentage().map_or(0.0, |p| p.0)
+                            },
                         },
                         preferred: Au(0),
                         constrained: false,
diff --git a/components/layout/table_row.rs b/components/layout/table_row.rs
index 90c3c812f1c..52412d9a2d1 100644
--- a/components/layout/table_row.rs
+++ b/components/layout/table_row.rs
@@ -430,25 +430,24 @@ impl Flow for TableRowFlow {
                 let child_base = kid.mut_base();
                 let child_column_inline_size = ColumnIntrinsicInlineSize {
                     minimum_length: match child_specified_inline_size {
-                        LengthOrPercentageOrAuto::Auto |
-                        LengthOrPercentageOrAuto::Calc(_) |
-                        LengthOrPercentageOrAuto::Percentage(_) => {
-                            child_base.intrinsic_inline_sizes.minimum_inline_size
+                        LengthOrPercentageOrAuto::Auto => None,
+                        LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                            lp.maybe_to_used_value(None)
                         },
-                        LengthOrPercentageOrAuto::Length(length) => Au::from(length),
-                    },
+                    }
+                    .unwrap_or(child_base.intrinsic_inline_sizes.minimum_inline_size),
                     percentage: match child_specified_inline_size {
-                        LengthOrPercentageOrAuto::Auto |
-                        LengthOrPercentageOrAuto::Calc(_) |
-                        LengthOrPercentageOrAuto::Length(_) => 0.0,
-                        LengthOrPercentageOrAuto::Percentage(percentage) => percentage.0,
+                        LengthOrPercentageOrAuto::Auto => 0.0,
+                        LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                            lp.as_percentage().map_or(0.0, |p| p.0)
+                        },
                     },
                     preferred: child_base.intrinsic_inline_sizes.preferred_inline_size,
                     constrained: match child_specified_inline_size {
-                        LengthOrPercentageOrAuto::Length(_) => true,
-                        LengthOrPercentageOrAuto::Auto |
-                        LengthOrPercentageOrAuto::Calc(_) |
-                        LengthOrPercentageOrAuto::Percentage(_) => false,
+                        LengthOrPercentageOrAuto::Auto => false,
+                        LengthOrPercentageOrAuto::LengthOrPercentage(ref lp) => {
+                            lp.maybe_to_used_value(None).is_some()
+                        },
                     },
                 };
                 min_inline_size = min_inline_size + child_column_inline_size.minimum_length;
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 233d4a01bb3..6feb6381b77 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -718,7 +718,9 @@ impl LayoutElementHelpers for LayoutDom<Element> {
                 specified::NoCalcLength::ServoCharacterWidth(specified::CharacterWidth(size));
             hints.push(from_declaration(
                 shared_lock,
-                PropertyDeclaration::Width(specified::LengthOrPercentageOrAuto::Length(value)),
+                PropertyDeclaration::Width(specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                    specified::LengthOrPercentage::Length(value)
+                )),
             ));
         }
 
@@ -743,8 +745,10 @@ impl LayoutElementHelpers for LayoutDom<Element> {
         match width {
             LengthOrPercentageOrAuto::Auto => {},
             LengthOrPercentageOrAuto::Percentage(percentage) => {
-                let width_value = specified::LengthOrPercentageOrAuto::Percentage(
-                    computed::Percentage(percentage),
+                let width_value = specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                    specified::LengthOrPercentage::Percentage(
+                        computed::Percentage(percentage),
+                    ),
                 );
                 hints.push(from_declaration(
                     shared_lock,
@@ -753,9 +757,13 @@ impl LayoutElementHelpers for LayoutDom<Element> {
             },
             LengthOrPercentageOrAuto::Length(length) => {
                 let width_value =
-                    specified::LengthOrPercentageOrAuto::Length(specified::NoCalcLength::Absolute(
-                        specified::AbsoluteLength::Px(length.to_f32_px()),
-                    ));
+                    specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                        specified::LengthOrPercentage::Length(
+                            specified::NoCalcLength::Absolute(
+                                specified::AbsoluteLength::Px(length.to_f32_px()),
+                            ),
+                        ),
+                    );
                 hints.push(from_declaration(
                     shared_lock,
                     PropertyDeclaration::Width(width_value),
@@ -776,8 +784,10 @@ impl LayoutElementHelpers for LayoutDom<Element> {
         match height {
             LengthOrPercentageOrAuto::Auto => {},
             LengthOrPercentageOrAuto::Percentage(percentage) => {
-                let height_value = specified::LengthOrPercentageOrAuto::Percentage(
-                    computed::Percentage(percentage),
+                let height_value = specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                    specified::LengthOrPercentage::Percentage(
+                        computed::Percentage(percentage),
+                    )
                 );
                 hints.push(from_declaration(
                     shared_lock,
@@ -786,9 +796,13 @@ impl LayoutElementHelpers for LayoutDom<Element> {
             },
             LengthOrPercentageOrAuto::Length(length) => {
                 let height_value =
-                    specified::LengthOrPercentageOrAuto::Length(specified::NoCalcLength::Absolute(
-                        specified::AbsoluteLength::Px(length.to_f32_px()),
-                    ));
+                    specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                        specified::LengthOrPercentage::Length(
+                            specified::NoCalcLength::Absolute(
+                                specified::AbsoluteLength::Px(length.to_f32_px()),
+                            )
+                        )
+                    );
                 hints.push(from_declaration(
                     shared_lock,
                     PropertyDeclaration::Height(height_value),
@@ -815,7 +829,9 @@ impl LayoutElementHelpers for LayoutDom<Element> {
                 specified::NoCalcLength::ServoCharacterWidth(specified::CharacterWidth(cols));
             hints.push(from_declaration(
                 shared_lock,
-                PropertyDeclaration::Width(specified::LengthOrPercentageOrAuto::Length(value)),
+                PropertyDeclaration::Width(specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                    specified::LengthOrPercentage::Length(value)
+                )),
             ));
         }
 
@@ -837,7 +853,9 @@ impl LayoutElementHelpers for LayoutDom<Element> {
             ));
             hints.push(from_declaration(
                 shared_lock,
-                PropertyDeclaration::Height(specified::LengthOrPercentageOrAuto::Length(value)),
+                PropertyDeclaration::Height(specified::LengthOrPercentageOrAuto::LengthOrPercentage(
+                    specified::LengthOrPercentage::Length(value)
+                )),
             ));
         }
 
diff --git a/components/style/properties/longhands/position.mako.rs b/components/style/properties/longhands/position.mako.rs
index 53a3acf81ec..ddba7255008 100644
--- a/components/style/properties/longhands/position.mako.rs
+++ b/components/style/properties/longhands/position.mako.rs
@@ -297,7 +297,7 @@ ${helpers.predefined_type(
         ${helpers.predefined_type(
             "min-%s" % size,
             "LengthOrPercentage",
-            "computed::LengthOrPercentage::Length(computed::Length::new(0.))",
+            "computed::LengthOrPercentage::zero()",
             "parse_non_negative",
             spec=spec % ("min-%s" % size),
             logical_group="min-size",
diff --git a/tests/unit/style/animated_properties.rs b/tests/unit/style/animated_properties.rs
index 06102bc840e..8fa45a6305f 100644
--- a/tests/unit/style/animated_properties.rs
+++ b/tests/unit/style/animated_properties.rs
@@ -4,7 +4,6 @@
 
 use cssparser::RGBA;
 use style::values::animated::{Animate, Procedure, ToAnimatedValue};
-use style::values::computed::Percentage;
 use style::values::generics::transform::{Transform, TransformOperation};
 
 fn interpolate_rgba(from: RGBA, to: RGBA, progress: f64) -> RGBA {
@@ -83,60 +82,6 @@ fn test_rgba_color_interepolation_out_of_range_clamped_2() {
     );
 }
 
-// Transform
-#[test]
-fn test_transform_interpolation_on_translate() {
-    use style::values::computed::{CalcLengthOrPercentage, Length, LengthOrPercentage};
-
-    let from = Transform(vec![TransformOperation::Translate3D(
-        LengthOrPercentage::Length(Length::new(0.)),
-        LengthOrPercentage::Length(Length::new(100.)),
-        Length::new(25.),
-    )]);
-    let to = Transform(vec![TransformOperation::Translate3D(
-        LengthOrPercentage::Length(Length::new(100.)),
-        LengthOrPercentage::Length(Length::new(0.)),
-        Length::new(75.),
-    )]);
-    assert_eq!(
-        from.animate(&to, Procedure::Interpolate { progress: 0.5 })
-            .unwrap(),
-        Transform(vec![TransformOperation::Translate3D(
-            LengthOrPercentage::Length(Length::new(50.)),
-            LengthOrPercentage::Length(Length::new(50.)),
-            Length::new(50.),
-        )])
-    );
-
-    let from = Transform(vec![TransformOperation::Translate3D(
-        LengthOrPercentage::Percentage(Percentage(0.5)),
-        LengthOrPercentage::Percentage(Percentage(1.0)),
-        Length::new(25.),
-    )]);
-    let to = Transform(vec![TransformOperation::Translate3D(
-        LengthOrPercentage::Length(Length::new(100.)),
-        LengthOrPercentage::Length(Length::new(50.)),
-        Length::new(75.),
-    )]);
-    assert_eq!(
-        from.animate(&to, Procedure::Interpolate { progress: 0.5 })
-            .unwrap(),
-        Transform(vec![TransformOperation::Translate3D(
-            // calc(50px + 25%)
-            LengthOrPercentage::Calc(CalcLengthOrPercentage::new(
-                Length::new(50.),
-                Some(Percentage(0.25))
-            )),
-            // calc(25px + 50%)
-            LengthOrPercentage::Calc(CalcLengthOrPercentage::new(
-                Length::new(25.),
-                Some(Percentage(0.5))
-            )),
-            Length::new(50.),
-        )])
-    );
-}
-
 #[test]
 fn test_transform_interpolation_on_scale() {
     let from = Transform(vec![TransformOperation::Scale3D(1.0, 2.0, 1.0)]);
@@ -197,29 +142,3 @@ fn test_transform_interpolation_on_skew() {
         )])
     );
 }
-
-#[test]
-fn test_transform_interpolation_on_mismatched_lists() {
-    use style::values::computed::{Angle, Length, LengthOrPercentage};
-
-    let from = Transform(vec![TransformOperation::Rotate3D(
-        0.0,
-        0.0,
-        1.0,
-        Angle::from_radians(100.0),
-    )]);
-    let to = Transform(vec![TransformOperation::Translate3D(
-        LengthOrPercentage::Length(Length::new(100.)),
-        LengthOrPercentage::Length(Length::new(0.)),
-        Length::new(0.),
-    )]);
-    assert_eq!(
-        from.animate(&to, Procedure::Interpolate { progress: 0.5 })
-            .unwrap(),
-        Transform(vec![TransformOperation::InterpolateMatrix {
-            from_list: from.clone(),
-            to_list: to.clone(),
-            progress: Percentage(0.5),
-        }])
-    );
-}
diff --git a/tests/unit/style/attr.rs b/tests/unit/style/attr.rs
index 4521d83239a..261d6d8f98b 100644
--- a/tests/unit/style/attr.rs
+++ b/tests/unit/style/attr.rs
@@ -4,19 +4,6 @@
 
 use app_units::Au;
 use style::attr::{parse_length, AttrValue, LengthOrPercentageOrAuto};
-use style::values::computed::{CalcLengthOrPercentage, Percentage};
-
-#[test]
-fn test_length_calc() {
-    let calc = CalcLengthOrPercentage::new(Au(10).into(), Some(Percentage(0.2)));
-    assert_eq!(calc.to_used_value(Some(Au(10))), Some(Au(12)));
-    assert_eq!(calc.to_used_value(Some(Au(0))), Some(Au(10)));
-    assert_eq!(calc.to_used_value(None), None);
-
-    let calc = CalcLengthOrPercentage::new(Au(10).into(), None);
-    assert_eq!(calc.to_used_value(Some(Au(0))), Some(Au(10)));
-    assert_eq!(calc.to_used_value(None), Some(Au(10)));
-}
 
 #[test]
 fn test_parse_double() {
diff --git a/tests/unit/style/properties/serialization.rs b/tests/unit/style/properties/serialization.rs
index 035f9a9385c..8853ab010dd 100644
--- a/tests/unit/style/properties/serialization.rs
+++ b/tests/unit/style/properties/serialization.rs
@@ -4,13 +4,11 @@
 
 use crate::properties::{parse, parse_input};
 use crate::stylesheets::block_from;
-use style::computed_values::display::T as Display;
 use style::properties::declaration_block::PropertyDeclarationBlock;
 use style::properties::parse_property_declaration_list;
 use style::properties::{Importance, PropertyDeclaration};
 use style::values::specified::url::SpecifiedUrl;
-use style::values::specified::NoCalcLength;
-use style::values::specified::{Length, LengthOrPercentage, LengthOrPercentageOrAuto};
+use style::values::specified::Length;
 use style_traits::ToCss;
 
 trait ToCssString {
@@ -25,53 +23,6 @@ impl ToCssString for PropertyDeclarationBlock {
     }
 }
 
-#[test]
-fn property_declaration_block_should_serialize_correctly() {
-    use style::properties::longhands::overflow_x::SpecifiedValue as OverflowValue;
-
-    let declarations = vec![
-        (
-            PropertyDeclaration::Width(LengthOrPercentageOrAuto::Length(NoCalcLength::from_px(
-                70f32,
-            ))),
-            Importance::Normal,
-        ),
-        (
-            PropertyDeclaration::MinHeight(LengthOrPercentage::Length(NoCalcLength::from_px(
-                20f32,
-            ))),
-            Importance::Normal,
-        ),
-        (
-            PropertyDeclaration::Height(LengthOrPercentageOrAuto::Length(NoCalcLength::from_px(
-                20f32,
-            ))),
-            Importance::Important,
-        ),
-        (
-            PropertyDeclaration::Display(Display::InlineBlock),
-            Importance::Normal,
-        ),
-        (
-            PropertyDeclaration::OverflowX(OverflowValue::Auto),
-            Importance::Normal,
-        ),
-        (
-            PropertyDeclaration::OverflowY(OverflowValue::Auto),
-            Importance::Normal,
-        ),
-    ];
-
-    let block = block_from(declarations);
-
-    let css_string = block.to_css_string();
-
-    assert_eq!(
-        css_string,
-        "width: 70px; min-height: 20px; height: 20px !important; display: inline-block; overflow: auto;"
-    );
-}
-
 mod shorthand_serialization {
     pub use super::*;
 
diff --git a/tests/unit/style/stylesheets.rs b/tests/unit/style/stylesheets.rs
index a0557ad8795..68bbff46f9f 100644
--- a/tests/unit/style/stylesheets.rs
+++ b/tests/unit/style/stylesheets.rs
@@ -17,20 +17,16 @@ use std::sync::atomic::AtomicBool;
 use style::context::QuirksMode;
 use style::error_reporting::{ContextualParseError, ParseErrorReporter};
 use style::media_queries::MediaList;
-use style::properties::longhands::{self, animation_timing_function};
+use style::properties::longhands;
 use style::properties::{CSSWideKeyword, CustomDeclaration};
 use style::properties::{CustomDeclarationValue, Importance};
 use style::properties::{PropertyDeclaration, PropertyDeclarationBlock};
 use style::shared_lock::SharedRwLock;
-use style::stylesheets::keyframes_rule::{Keyframe, KeyframePercentage, KeyframeSelector};
 use style::stylesheets::{
-    CssRule, CssRules, KeyframesRule, NamespaceRule, StyleRule, Stylesheet, StylesheetContents,
+    CssRule, CssRules, NamespaceRule, StyleRule, Stylesheet, StylesheetContents,
 };
 use style::stylesheets::{Namespaces, Origin};
-use style::values::computed::Percentage;
-use style::values::specified::TimingFunction;
-use style::values::specified::{LengthOrPercentageOrAuto, PositionComponent};
-use style::values::{CustomIdent, KeyframesName};
+use style::values::specified::PositionComponent;
 
 pub fn block_from<I>(iterable: I) -> PropertyDeclarationBlock
 where
@@ -61,14 +57,6 @@ fn test_parse_stylesheet() {
             display: block;
         }
         #d1 > .ok { background: blue; }
-        @keyframes foo {
-            from { width: 0% }
-            to {
-                width: 100%;
-                width: 50% !important; /* !important not allowed here */
-                animation-name: 'foo'; /* animation properties not allowed here */
-                animation-timing-function: ease; /* … except animation-timing-function */
-            }
         }";
     let url = ServoUrl::parse("about::test").unwrap();
     let lock = SharedRwLock::new();
@@ -278,56 +266,6 @@ fn test_parse_stylesheet() {
                             column: 9,
                         },
                     }))),
-                    CssRule::Keyframes(Arc::new(stylesheet.shared_lock.wrap(KeyframesRule {
-                        name: KeyframesName::Ident(CustomIdent("foo".into())),
-                        keyframes: vec![
-                            Arc::new(stylesheet.shared_lock.wrap(Keyframe {
-                                selector: KeyframeSelector::new_for_unit_testing(vec![
-                                    KeyframePercentage::new(0.),
-                                ]),
-                                block: Arc::new(stylesheet.shared_lock.wrap(block_from(vec![(
-                                    PropertyDeclaration::Width(
-                                        LengthOrPercentageOrAuto::Percentage(Percentage(0.)),
-                                    ),
-                                    Importance::Normal,
-                                )]))),
-                                source_location: SourceLocation {
-                                    line: 17,
-                                    column: 13,
-                                },
-                            })),
-                            Arc::new(stylesheet.shared_lock.wrap(Keyframe {
-                                selector: KeyframeSelector::new_for_unit_testing(vec![
-                                    KeyframePercentage::new(1.),
-                                ]),
-                                block: Arc::new(stylesheet.shared_lock.wrap(block_from(vec![
-                                    (
-                                        PropertyDeclaration::Width(
-                                            LengthOrPercentageOrAuto::Percentage(Percentage(1.)),
-                                        ),
-                                        Importance::Normal,
-                                    ),
-                                    (
-                                        PropertyDeclaration::AnimationTimingFunction(
-                                            animation_timing_function::SpecifiedValue(vec![
-                                                TimingFunction::ease(),
-                                            ]),
-                                        ),
-                                        Importance::Normal,
-                                    ),
-                                ]))),
-                                source_location: SourceLocation {
-                                    line: 18,
-                                    column: 13,
-                                },
-                            })),
-                        ],
-                        vendor_prefix: None,
-                        source_location: SourceLocation {
-                            line: 16,
-                            column: 19,
-                        },
-                    }))),
                 ],
                 &stylesheet.shared_lock,
             ),
diff --git a/tests/unit/style/viewport.rs b/tests/unit/style/viewport.rs
index 5855b11e114..41fc2539f39 100644
--- a/tests/unit/style/viewport.rs
+++ b/tests/unit/style/viewport.rs
@@ -17,6 +17,7 @@ use style::stylesheets::{CssRuleType, Origin, Stylesheet, StylesheetInDocument};
 use style::values::specified::LengthOrPercentageOrAuto::{self, Auto};
 use style::values::specified::NoCalcLength::{self, ViewportPercentage};
 use style::values::specified::ViewportPercentageLength::Vw;
+use style::values::specified::LengthOrPercentage;
 use style_traits::viewport::*;
 use style_traits::{ParsingMode, PinchZoomFactor};
 
@@ -96,14 +97,14 @@ macro_rules! assert_decl_len {
 
 macro_rules! viewport_length {
     ($value:expr, px) => {
-        ViewportLength::Specified(LengthOrPercentageOrAuto::Length(NoCalcLength::from_px(
+        ViewportLength::Specified(LengthOrPercentageOrAuto::LengthOrPercentage(LengthOrPercentage::Length(NoCalcLength::from_px(
             $value,
-        )))
+        ))))
     };
     ($value:expr, vw) => {
-        ViewportLength::Specified(LengthOrPercentageOrAuto::Length(ViewportPercentage(Vw(
+        ViewportLength::Specified(LengthOrPercentageOrAuto::LengthOrPercentage(LengthOrPercentage::Length(ViewportPercentage(Vw(
             $value,
-        ))))
+        )))))
     };
 }
 
diff --git a/tests/wpt/metadata/css/css-variables/variable-substitution-replaced-size.html.ini b/tests/wpt/metadata/css/css-variables/variable-substitution-replaced-size.html.ini
index d9922a6482f..07ba6517e69 100644
--- a/tests/wpt/metadata/css/css-variables/variable-substitution-replaced-size.html.ini
+++ b/tests/wpt/metadata/css/css-variables/variable-substitution-replaced-size.html.ini
@@ -1,6 +1,4 @@
 [variable-substitution-replaced-size.html]
-  [height on IFRAME]
-    expected: FAIL
 
   [width on INPUT]
     expected: FAIL
@@ -8,6 +6,3 @@
   [height on INPUT]
     expected: FAIL
 
-  [height on CANVAS]
-    expected: FAIL
-