Miscellaneous build / tidy fixes.

66 files changed, 564 insertions, 292 deletions

diff --git a/Cargo.lock b/Cargo.lock
index baaf758cb72..029cf147954 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "accountable-refcell"
 version = "0.2.0"
@@ -1171,9 +1173,9 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.27.2"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "754b69d351cdc2d8ee09ae203db831e005560fc6030da058f86ad60c92a9cb0a"
+checksum = "1db8599a9761b371751fbf13e076fa03c6e1a78f8c5288e6ab9467f10a2322c1"
 dependencies = [
  "cssparser-macros",
  "dtoa-short",
@@ -5214,7 +5216,6 @@ dependencies = [
  "precomputed-hash",
  "servo_arc",
  "smallvec 1.6.1",
- "thin-slice",
  "to_shmem",
  "to_shmem_derive",
 ]
diff --git a/components/canvas/Cargo.toml b/components/canvas/Cargo.toml
index f5e9dbcd47a..74545af1b93 100644
--- a/components/canvas/Cargo.toml
+++ b/components/canvas/Cargo.toml
@@ -20,7 +20,7 @@ bitflags = "1.0"
 byteorder = "1"
 canvas_traits = { path = "../canvas_traits" }
 crossbeam-channel = "0.4"
-cssparser = "0.27"
+cssparser = "0.28"
 euclid = "0.20"
 font-kit = "0.10"
 fnv = "1.0"
diff --git a/components/canvas_traits/Cargo.toml b/components/canvas_traits/Cargo.toml
index 8414349939c..d6d8290378e 100644
--- a/components/canvas_traits/Cargo.toml
+++ b/components/canvas_traits/Cargo.toml
@@ -16,7 +16,7 @@ xr-profile = ["webxr-api/profile", "time"]
 
 [dependencies]
 crossbeam-channel = "0.4"
-cssparser = "0.27"
+cssparser = "0.28"
 euclid = "0.20"
 ipc-channel = "0.14"
 lazy_static = "1"
diff --git a/components/derive_common/cg.rs b/components/derive_common/cg.rs
index 8abfd871496..ab4b8e52760 100644
--- a/components/derive_common/cg.rs
+++ b/components/derive_common/cg.rs
@@ -222,7 +222,12 @@ where
     }
 }
 
-fn map_type_params_in_path<F>(path: &Path, params: &[&TypeParam], self_type: &Path, f: &mut F) -> Path
+fn map_type_params_in_path<F>(
+    path: &Path,
+    params: &[&TypeParam],
+    self_type: &Path,
+    f: &mut F,
+) -> Path
 where
     F: FnMut(&Ident) -> Type,
 {
@@ -241,9 +246,9 @@ where
                                 .iter()
                                 .map(|arg| match arg {
                                     ty @ &GenericArgument::Lifetime(_) => ty.clone(),
-                                    &GenericArgument::Type(ref data) => {
-                                        GenericArgument::Type(map_type_params(data, params, self_type, f))
-                                    },
+                                    &GenericArgument::Type(ref data) => GenericArgument::Type(
+                                        map_type_params(data, params, self_type, f),
+                                    ),
                                     &GenericArgument::Binding(ref data) => {
                                         GenericArgument::Binding(Binding {
                                             ty: map_type_params(&data.ty, params, self_type, f),
diff --git a/components/layout/construct.rs b/components/layout/construct.rs
index 7078e063978..c17d52dd155 100644
--- a/components/layout/construct.rs
+++ b/components/layout/construct.rs
@@ -71,8 +71,8 @@ use style::logical_geometry::Direction;
 use style::properties::ComputedValues;
 use style::selector_parser::{PseudoElement, RestyleDamage};
 use style::servo::restyle_damage::ServoRestyleDamage;
+use style::values::computed::Image;
 use style::values::generics::counters::ContentItem;
-use style::values::generics::url::UrlOrNone as ImageUrlOrNone;
 
 /// The results of flow construction for a DOM node.
 #[derive(Clone)]
@@ -1506,9 +1506,9 @@ where
     ) -> ConstructionResult {
         let flotation = FloatKind::from_property(flotation);
         let marker_fragments = match node.style(self.style_context()).get_list().list_style_image {
-            ImageUrlOrNone::Url(ref url_value) => {
+            Image::Url(ref url_value) => {
                 let image_info = Box::new(ImageFragmentInfo::new(
-                    url_value.url().map(|u| u.clone()),
+                    url_value.url().cloned(),
                     None,
                     node,
                     &self.layout_context,
@@ -1519,7 +1519,13 @@ where
                     self.layout_context,
                 )]
             },
-            ImageUrlOrNone::None => match ListStyleTypeContent::from_list_style_type(
+            // XXX: Non-None image types unimplemented.
+            Image::ImageSet(..) |
+            Image::Rect(..) |
+            Image::Gradient(..) |
+            Image::PaintWorklet(..) |
+            Image::CrossFade(..) |
+            Image::None => match ListStyleTypeContent::from_list_style_type(
                 node.style(self.style_context()).get_list().list_style_type,
             ) {
                 ListStyleTypeContent::None => Vec::new(),
diff --git a/components/layout/display_list/builder.rs b/components/layout/display_list/builder.rs
index d268f8428d3..8f087e1c6c2 100644
--- a/components/layout/display_list/builder.rs
+++ b/components/layout/display_list/builder.rs
@@ -792,6 +792,9 @@ impl Fragment {
                         );
                     }
                 },
+                Image::CrossFade(..) | Image::ImageSet(..) => {
+                    unreachable!("Shouldn't be parsed by Servo for now")
+                },
                 Image::Rect(ref rect) => {
                     // This is a (boxed) empty enum on non-Gecko
                     match **rect {}
diff --git a/components/layout/query.rs b/components/layout/query.rs
index 56b1fc7d0f8..a02a5c935c2 100644
--- a/components/layout/query.rs
+++ b/components/layout/query.rs
@@ -47,6 +47,7 @@ use style::properties::{
 };
 use style::selector_parser::PseudoElement;
 use style::shared_lock::SharedRwLock;
+use style::stylesheets::{CssRuleType, Origin};
 use style_traits::{CSSPixel, ParsingMode, ToCss};
 use webrender_api::ExternalScrollId;
 
@@ -762,10 +763,12 @@ fn create_font_declaration(
         &mut declarations,
         property.clone(),
         value,
+        Origin::Author,
         url_data,
         None,
         ParsingMode::DEFAULT,
         quirks_mode,
+        CssRuleType::Style,
     );
     let declarations = match result {
         Ok(()) => {
diff --git a/components/layout_2020/Cargo.toml b/components/layout_2020/Cargo.toml
index 75a948fa56d..24e3ead663b 100644
--- a/components/layout_2020/Cargo.toml
+++ b/components/layout_2020/Cargo.toml
@@ -16,7 +16,7 @@ doctest = false
 app_units = "0.7"
 atomic_refcell = "0.1.6"
 canvas_traits = { path = "../canvas_traits" }
-cssparser = "0.27"
+cssparser = "0.28"
 embedder_traits = { path = "../embedder_traits" }
 euclid = "0.20"
 fnv = "1.0"
diff --git a/components/layout_2020/display_list/mod.rs b/components/layout_2020/display_list/mod.rs
index 4fc0c390d0d..3f77e4ae362 100644
--- a/components/layout_2020/display_list/mod.rs
+++ b/components/layout_2020/display_list/mod.rs
@@ -474,6 +474,9 @@ impl<'a> BuilderForBoxFragment<'a> {
                 },
                 // Gecko-only value, represented as a (boxed) empty enum on non-Gecko.
                 Image::Rect(ref rect) => match **rect {},
+                Image::ImageSet(..) | Image::CrossFade(..) => {
+                    unreachable!("Shouldn't be parsed on Servo for now")
+                },
             }
         }
     }
diff --git a/components/layout_2020/lists.rs b/components/layout_2020/lists.rs
index c8fa7eabee3..99074747599 100644
--- a/components/layout_2020/lists.rs
+++ b/components/layout_2020/lists.rs
@@ -7,7 +7,7 @@ use crate::dom_traversal::{NodeAndStyleInfo, NodeExt, PseudoElementContentItem};
 use crate::replaced::ReplacedContent;
 use style::properties::longhands::list_style_type::computed_value::T as ListStyleType;
 use style::properties::style_structs;
-use style::values::computed::url::UrlOrNone;
+use style::values::computed::Image;
 
 /// https://drafts.csswg.org/css-lists/#content-property
 pub(crate) fn make_marker<'dom, Node>(
@@ -21,13 +21,18 @@ where
 
     // https://drafts.csswg.org/css-lists/#marker-image
     let marker_image = || match &style.list_style_image {
-        UrlOrNone::Url(url) => Some(vec![
+        Image::Url(url) => Some(vec![
             PseudoElementContentItem::Replaced(ReplacedContent::from_image_url(
                 info.node, context, url,
             )?),
             PseudoElementContentItem::Text(" ".into()),
         ]),
-        UrlOrNone::None => None,
+        // XXX: Non-None image types unimplemented.
+        Image::ImageSet(..) |
+        Image::Rect(..) |
+        Image::Gradient(..) |
+        Image::CrossFade(..) |
+        Image::None => None,
     };
     marker_image().or_else(|| {
         Some(vec![PseudoElementContentItem::Text(
diff --git a/components/layout_thread/dom_wrapper.rs b/components/layout_thread/dom_wrapper.rs
index f0d25ff8c49..cfbc207431a 100644
--- a/components/layout_thread/dom_wrapper.rs
+++ b/components/layout_thread/dom_wrapper.rs
@@ -90,6 +90,7 @@ use style::shared_lock::{
 };
 use style::str::is_whitespace;
 use style::stylist::CascadeData;
+use style::values::{AtomIdent, AtomString};
 use style::CaseSensitivityExt;
 
 #[derive(Clone, Copy)]
@@ -500,8 +501,8 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn has_attr(&self, namespace: &Namespace, attr: &LocalName) -> bool {
-        self.get_attr(namespace, attr).is_some()
+    fn has_attr(&self, namespace: &style::Namespace, attr: &style::LocalName) -> bool {
+        self.get_attr(&**namespace, &**attr).is_some()
     }
 
     #[inline]
@@ -512,11 +513,11 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     #[inline(always)]
     fn each_class<F>(&self, mut callback: F)
     where
-        F: FnMut(&Atom),
+        F: FnMut(&AtomIdent),
     {
         if let Some(ref classes) = self.element.get_classes_for_layout() {
             for class in *classes {
-                callback(class)
+                callback(AtomIdent::cast(class))
             }
         }
     }
@@ -640,7 +641,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     fn lang_attr(&self) -> Option<SelectorAttrValue> {
         self.get_attr(&ns!(xml), &local_name!("lang"))
             .or_else(|| self.get_attr(&ns!(), &local_name!("lang")))
-            .map(|v| String::from(v as &str))
+            .map(|v| SelectorAttrValue::from(v as &str))
     }
 
     fn match_element_lang(
@@ -663,8 +664,8 @@ impl<'le> TElement for ServoLayoutElement<'le> {
         // so we can decide when to fall back to the Content-Language check.
         let element_lang = match override_lang {
             Some(Some(lang)) => lang,
-            Some(None) => String::new(),
-            None => self.element.get_lang_for_layout(),
+            Some(None) => AtomString::default(),
+            None => AtomString::from(&*self.element.get_lang_for_layout()),
         };
         extended_filtering(&element_lang, &*value)
     }
@@ -813,9 +814,9 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
 
     fn attr_matches(
         &self,
-        ns: &NamespaceConstraint<&Namespace>,
-        local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        ns: &NamespaceConstraint<&style::Namespace>,
+        local_name: &style::LocalName,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
@@ -945,7 +946,7 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn has_id(&self, id: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_id(&self, id: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         unsafe {
             (*self.element.id_attribute())
                 .as_ref()
@@ -954,16 +955,16 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         None
     }
 
     #[inline]
-    fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class(&self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         self.element.has_class_for_layout(name, case_sensitivity)
     }
 
@@ -1434,9 +1435,9 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
 
     fn attr_matches(
         &self,
-        ns: &NamespaceConstraint<&Namespace>,
-        local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        ns: &NamespaceConstraint<&style::Namespace>,
+        local_name: &style::LocalName,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
@@ -1470,23 +1471,23 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
         false
     }
 
-    fn has_id(&self, _id: &Atom, _case_sensitivity: CaseSensitivity) -> bool {
+    fn has_id(&self, _id: &AtomIdent, _case_sensitivity: CaseSensitivity) -> bool {
         debug!("ServoThreadSafeLayoutElement::has_id called");
         false
     }
 
     #[inline]
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         debug!("ServoThreadSafeLayoutElement::is_part called");
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         debug!("ServoThreadSafeLayoutElement::imported_part called");
         None
     }
 
-    fn has_class(&self, _name: &Atom, _case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class(&self, _name: &AtomIdent, _case_sensitivity: CaseSensitivity) -> bool {
         debug!("ServoThreadSafeLayoutElement::has_class called");
         false
     }
diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index 74deb9fb907..ba2a1f27f68 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -506,6 +506,7 @@ impl LayoutThread {
 
         let device = Device::new(
             MediaType::screen(),
+            QuirksMode::NoQuirks,
             window_size.initial_viewport,
             window_size.device_pixel_ratio,
         );
@@ -1267,7 +1268,12 @@ impl LayoutThread {
         };
 
         let had_used_viewport_units = self.stylist.device().used_viewport_units();
-        let device = Device::new(MediaType::screen(), initial_viewport, device_pixel_ratio);
+        let device = Device::new(
+            MediaType::screen(),
+            self.stylist.quirks_mode(),
+            initial_viewport,
+            device_pixel_ratio,
+        );
         let sheet_origins_affected_by_device_change = self.stylist.set_device(device, &guards);
 
         self.stylist
diff --git a/components/layout_thread_2020/dom_wrapper.rs b/components/layout_thread_2020/dom_wrapper.rs
index d3c355c2fe7..e37bbd38274 100644
--- a/components/layout_thread_2020/dom_wrapper.rs
+++ b/components/layout_thread_2020/dom_wrapper.rs
@@ -90,6 +90,7 @@ use style::shared_lock::{
 };
 use style::str::is_whitespace;
 use style::stylist::CascadeData;
+use style::values::{AtomIdent, AtomString};
 use style::CaseSensitivityExt;
 
 #[derive(Clone, Copy)]
@@ -508,7 +509,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn has_attr(&self, namespace: &Namespace, attr: &LocalName) -> bool {
+    fn has_attr(&self, namespace: &style::Namespace, attr: &style::LocalName) -> bool {
         self.get_attr(namespace, attr).is_some()
     }
 
@@ -520,11 +521,11 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     #[inline(always)]
     fn each_class<F>(&self, mut callback: F)
     where
-        F: FnMut(&Atom),
+        F: FnMut(&AtomIdent),
     {
         if let Some(ref classes) = self.element.get_classes_for_layout() {
             for class in *classes {
-                callback(class)
+                callback(AtomIdent::cast(class))
             }
         }
     }
@@ -648,7 +649,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
     fn lang_attr(&self) -> Option<SelectorAttrValue> {
         self.get_attr(&ns!(xml), &local_name!("lang"))
             .or_else(|| self.get_attr(&ns!(), &local_name!("lang")))
-            .map(|v| String::from(v as &str))
+            .map(|v| SelectorAttrValue::from(v as &str))
     }
 
     fn match_element_lang(
@@ -671,8 +672,8 @@ impl<'le> TElement for ServoLayoutElement<'le> {
         // so we can decide when to fall back to the Content-Language check.
         let element_lang = match override_lang {
             Some(Some(lang)) => lang,
-            Some(None) => String::new(),
-            None => self.element.get_lang_for_layout(),
+            Some(None) => AtomString::default(),
+            None => AtomString::from(&*self.element.get_lang_for_layout()),
         };
         extended_filtering(&element_lang, &*value)
     }
@@ -821,9 +822,9 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
 
     fn attr_matches(
         &self,
-        ns: &NamespaceConstraint<&Namespace>,
-        local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        ns: &NamespaceConstraint<&style::Namespace>,
+        local_name: &style::LocalName,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
@@ -953,7 +954,7 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn has_id(&self, id: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_id(&self, id: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         unsafe {
             (*self.element.id_attribute())
                 .as_ref()
@@ -962,16 +963,16 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
     }
 
     #[inline]
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         None
     }
 
     #[inline]
-    fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class(&self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         self.element.has_class_for_layout(name, case_sensitivity)
     }
 
@@ -1445,9 +1446,9 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
 
     fn attr_matches(
         &self,
-        ns: &NamespaceConstraint<&Namespace>,
-        local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        ns: &NamespaceConstraint<&style::Namespace>,
+        local_name: &style::LocalName,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
@@ -1479,23 +1480,23 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
         false
     }
 
-    fn has_id(&self, _id: &Atom, _case_sensitivity: CaseSensitivity) -> bool {
+    fn has_id(&self, _id: &AtomIdent, _case_sensitivity: CaseSensitivity) -> bool {
         debug!("ServoThreadSafeLayoutElement::has_id called");
         false
     }
 
     #[inline]
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         debug!("ServoThreadSafeLayoutElement::is_part called");
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         debug!("ServoThreadSafeLayoutElement::imported_part called");
         None
     }
 
-    fn has_class(&self, _name: &Atom, _case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class(&self, _name: &AtomIdent, _case_sensitivity: CaseSensitivity) -> bool {
         debug!("ServoThreadSafeLayoutElement::has_class called");
         false
     }
diff --git a/components/layout_thread_2020/lib.rs b/components/layout_thread_2020/lib.rs
index 41ceddc5d44..6b32a44a5b4 100644
--- a/components/layout_thread_2020/lib.rs
+++ b/components/layout_thread_2020/lib.rs
@@ -474,6 +474,7 @@ impl LayoutThread {
         // but it will be set correctly when the initial reflow takes place.
         let device = Device::new(
             MediaType::screen(),
+            QuirksMode::NoQuirks,
             window_size.initial_viewport,
             window_size.device_pixel_ratio,
         );
@@ -952,7 +953,12 @@ impl LayoutThread {
             ua_or_user: &ua_or_user_guard,
         };
 
-        let device = Device::new(MediaType::screen(), initial_viewport, device_pixel_ratio);
+        let device = Device::new(
+            MediaType::screen(),
+            self.stylist.quirks_mode(),
+            initial_viewport,
+            device_pixel_ratio,
+        );
         let sheet_origins_affected_by_device_change = self.stylist.set_device(device, &guards);
 
         self.stylist
diff --git a/components/malloc_size_of/Cargo.toml b/components/malloc_size_of/Cargo.toml
index 3f6d6e80ed9..f3b40bfa0d6 100644
--- a/components/malloc_size_of/Cargo.toml
+++ b/components/malloc_size_of/Cargo.toml
@@ -31,8 +31,8 @@ accountable-refcell = { version = "0.2.0", optional = true }
 app_units = "0.7"
 content-security-policy = { version = "0.4.0", features = ["serde"], optional = true }
 crossbeam-channel = { version = "0.4", optional = true }
-cssparser = "0.27"
-euclid = "0.22"
+cssparser = "0.28"
+euclid = "0.20"
 hashglobe = { path = "../hashglobe" }
 hyper = { version = "0.12", optional = true }
 hyper_serde = { version = "0.11", optional = true }
diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 68ac6638907..a09ccf8f257 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -42,7 +42,7 @@ chrono = "0.4"
 content-security-policy = { version = "0.4.0", features = ["serde"] }
 cookie = "0.11"
 crossbeam-channel = "0.4"
-cssparser = "0.27"
+cssparser = "0.28"
 data-url = "0.1.0"
 deny_public_fields = { path = "../deny_public_fields" }
 devtools_traits = { path = "../devtools_traits" }
diff --git a/components/script/dom/attr.rs b/components/script/dom/attr.rs
index e2e8b79f9af..9c4b221f6f3 100644
--- a/components/script/dom/attr.rs
+++ b/components/script/dom/attr.rs
@@ -21,6 +21,7 @@ use servo_atoms::Atom;
 use std::borrow::ToOwned;
 use std::mem;
 use style::attr::{AttrIdentifier, AttrValue};
+use style::values::GenericAtomIdent;
 
 // https://dom.spec.whatwg.org/#interface-attr
 #[dom_struct]
@@ -46,10 +47,10 @@ impl Attr {
         Attr {
             node_: Node::new_inherited(document),
             identifier: AttrIdentifier {
-                local_name: local_name,
-                name: name,
-                namespace: namespace,
-                prefix: prefix,
+                local_name: GenericAtomIdent(local_name),
+                name: GenericAtomIdent(name),
+                namespace: GenericAtomIdent(namespace),
+                prefix: prefix.map(GenericAtomIdent),
             },
             value: DomRefCell::new(value),
             owner: MutNullableDom::new(owner),
@@ -75,17 +76,17 @@ impl Attr {
 
     #[inline]
     pub fn name(&self) -> &LocalName {
-        &self.identifier.name
+        &self.identifier.name.0
     }
 
     #[inline]
     pub fn namespace(&self) -> &Namespace {
-        &self.identifier.namespace
+        &self.identifier.namespace.0
     }
 
     #[inline]
     pub fn prefix(&self) -> Option<&Prefix> {
-        self.identifier.prefix.as_ref()
+        Some(&self.identifier.prefix.as_ref()?.0)
     }
 }
 
@@ -105,7 +106,7 @@ impl AttrMethods for Attr {
     // https://dom.spec.whatwg.org/#dom-attr-value
     fn SetValue(&self, value: DOMString) {
         if let Some(owner) = self.owner() {
-            let value = owner.parse_attribute(&self.identifier.namespace, self.local_name(), value);
+            let value = owner.parse_attribute(self.namespace(), self.local_name(), value);
             self.set_value(value, &owner);
         } else {
             *self.value.borrow_mut() = AttrValue::String(value.into());
@@ -115,12 +116,12 @@ impl AttrMethods for Attr {
     // https://dom.spec.whatwg.org/#dom-attr-name
     fn Name(&self) -> DOMString {
         // FIXME(ajeffrey): convert directly from LocalName to DOMString
-        DOMString::from(&*self.identifier.name)
+        DOMString::from(&**self.name())
     }
 
     // https://dom.spec.whatwg.org/#dom-attr-namespaceuri
     fn GetNamespaceURI(&self) -> Option<DOMString> {
-        match self.identifier.namespace {
+        match *self.namespace() {
             ns!() => None,
             ref url => Some(DOMString::from(&**url)),
         }
@@ -170,7 +171,7 @@ impl Attr {
         assert_eq!(Some(owner), self.owner().as_deref());
         owner.will_mutate_attr(self);
         self.swap_value(&mut value);
-        if self.identifier.namespace == ns!() {
+        if *self.namespace() == ns!() {
             vtable_for(owner.upcast())
                 .attribute_mutated(self, AttributeMutation::Set(Some(&value)));
         }
@@ -196,7 +197,7 @@ impl Attr {
     /// Sets the owner element. Should be called after the attribute is added
     /// or removed from its older parent.
     pub fn set_owner(&self, owner: Option<&Element>) {
-        let ns = &self.identifier.namespace;
+        let ns = self.namespace();
         match (self.owner(), owner) {
             (Some(old), None) => {
                 // Already gone from the list of attributes of old owner.
@@ -218,7 +219,7 @@ impl Attr {
 
     pub fn summarize(&self) -> AttrInfo {
         AttrInfo {
-            namespace: (*self.identifier.namespace).to_owned(),
+            namespace: (**self.namespace()).to_owned(),
             name: String::from(self.Name()),
             value: String::from(self.Value()),
         }
@@ -263,11 +264,11 @@ impl<'dom> AttrHelpersForLayout<'dom> for LayoutDom<'dom, Attr> {
 
     #[inline]
     fn local_name(self) -> &'dom LocalName {
-        unsafe { &self.unsafe_get().identifier.local_name }
+        unsafe { &self.unsafe_get().identifier.local_name.0 }
     }
 
     #[inline]
     fn namespace(self) -> &'dom Namespace {
-        unsafe { &self.unsafe_get().identifier.namespace }
+        unsafe { &self.unsafe_get().identifier.namespace.0 }
     }
 }
diff --git a/components/script/dom/css.rs b/components/script/dom/css.rs
index 138ffb6b9da..8c9600549c5 100644
--- a/components/script/dom/css.rs
+++ b/components/script/dom/css.rs
@@ -14,7 +14,7 @@ use dom_struct::dom_struct;
 use style::context::QuirksMode;
 use style::parser::ParserContext;
 use style::stylesheets::supports_rule::{parse_condition_or_declaration, Declaration};
-use style::stylesheets::CssRuleType;
+use style::stylesheets::{CssRuleType, Origin};
 use style_traits::ParsingMode;
 
 #[dom_struct]
@@ -39,7 +39,8 @@ impl CSS {
         decl.push_str(&value);
         let decl = Declaration(decl);
         let url = win.Document().url();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Style),
             ParsingMode::DEFAULT,
@@ -60,7 +61,8 @@ impl CSS {
         };
 
         let url = win.Document().url();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Style),
             ParsingMode::DEFAULT,
diff --git a/components/script/dom/cssmediarule.rs b/components/script/dom/cssmediarule.rs
index 2f54b0a0839..ca2bdd4d447 100644
--- a/components/script/dom/cssmediarule.rs
+++ b/components/script/dom/cssmediarule.rs
@@ -18,7 +18,7 @@ use servo_arc::Arc;
 use style::media_queries::MediaList as StyleMediaList;
 use style::parser::ParserContext;
 use style::shared_lock::{Locked, ToCssWithGuard};
-use style::stylesheets::{CssRuleType, MediaRule};
+use style::stylesheets::{CssRuleType, MediaRule, Origin};
 use style_traits::{ParsingMode, ToCss};
 
 #[dom_struct]
@@ -82,7 +82,8 @@ impl CSSMediaRule {
         let window = global.as_window();
         let url = window.get_url();
         let quirks_mode = window.Document().quirks_mode();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
diff --git a/components/script/dom/cssnamespacerule.rs b/components/script/dom/cssnamespacerule.rs
index f3ff8df36d9..3a15c7d5ffd 100644
--- a/components/script/dom/cssnamespacerule.rs
+++ b/components/script/dom/cssnamespacerule.rs
@@ -63,7 +63,7 @@ impl CSSNamespaceRuleMethods for CSSNamespaceRule {
     // https://drafts.csswg.org/cssom/#dom-cssnamespacerule-namespaceuri
     fn NamespaceURI(&self) -> DOMString {
         let guard = self.cssrule.shared_lock().read();
-        (*self.namespacerule.read_with(&guard).url).into()
+        (**self.namespacerule.read_with(&guard).url).into()
     }
 }
 
diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index 3c0d63ce92f..41101afd625 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -25,6 +25,7 @@ use style::properties::{
 };
 use style::selector_parser::PseudoElement;
 use style::shared_lock::Locked;
+use style::stylesheets::{CssRuleType, Origin};
 use style_traits::ParsingMode;
 
 // http://dev.w3.org/csswg/cssom/#the-cssstyledeclaration-interface
@@ -302,10 +303,12 @@ impl CSSStyleDeclaration {
                 &mut declarations,
                 id,
                 &value,
+                Origin::Author,
                 &self.owner.base_url(),
                 window.css_error_reporter(),
                 ParsingMode::DEFAULT,
                 quirks_mode,
+                CssRuleType::Style,
             );
 
             // Step 6
@@ -461,6 +464,7 @@ impl CSSStyleDeclarationMethods for CSSStyleDeclaration {
                 &self.owner.base_url(),
                 window.css_error_reporter(),
                 quirks_mode,
+                CssRuleType::Style,
             );
         });
 
diff --git a/components/script/dom/csssupportsrule.rs b/components/script/dom/csssupportsrule.rs
index c462faf7eba..8a028e9efb2 100644
--- a/components/script/dom/csssupportsrule.rs
+++ b/components/script/dom/csssupportsrule.rs
@@ -16,7 +16,7 @@ use servo_arc::Arc;
 use style::parser::ParserContext;
 use style::shared_lock::{Locked, ToCssWithGuard};
 use style::stylesheets::supports_rule::SupportsCondition;
-use style::stylesheets::{CssRuleType, SupportsRule};
+use style::stylesheets::{CssRuleType, Origin, SupportsRule};
 use style_traits::{ParsingMode, ToCss};
 
 #[dom_struct]
@@ -71,7 +71,8 @@ impl CSSSupportsRule {
             let win = global.as_window();
             let url = win.Document().url();
             let quirks_mode = win.Document().quirks_mode();
-            let context = ParserContext::new_for_cssom(
+            let context = ParserContext::new(
+                Origin::Author,
                 &url,
                 Some(CssRuleType::Supports),
                 ParsingMode::DEFAULT,
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index eccc14f67ed..8ae80be66a1 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -3454,7 +3454,12 @@ impl Document {
         let window_size = self.window().window_size();
         let viewport_size = window_size.initial_viewport;
         let device_pixel_ratio = window_size.device_pixel_ratio;
-        Device::new(MediaType::screen(), viewport_size, device_pixel_ratio)
+        Device::new(
+            MediaType::screen(),
+            self.quirks_mode(),
+            viewport_size,
+            device_pixel_ratio,
+        )
     }
 
     pub fn salvageable(&self) -> bool {
@@ -3551,8 +3556,9 @@ impl Document {
         } else {
             snapshot.other_attributes_changed = true;
         }
-        if !snapshot.changed_attrs.contains(attr.local_name()) {
-            snapshot.changed_attrs.push(attr.local_name().clone());
+        let local_name = style::LocalName::cast(attr.local_name());
+        if !snapshot.changed_attrs.contains(local_name) {
+            snapshot.changed_attrs.push(local_name.clone());
         }
         if snapshot.attrs.is_none() {
             let attrs = el
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index d3813b34001..e69fd558f5c 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -129,9 +129,10 @@ use style::selector_parser::{
     NonTSPseudoClass, PseudoElement, RestyleDamage, SelectorImpl, SelectorParser,
 };
 use style::shared_lock::{Locked, SharedRwLock};
+use style::stylesheets::CssRuleType;
 use style::thread_state;
 use style::values::generics::NonNegative;
-use style::values::{computed, specified, CSSFloat};
+use style::values::{computed, specified, AtomIdent, AtomString, CSSFloat};
 use style::CaseSensitivityExt;
 use xml5ever::serialize as xmlSerialize;
 use xml5ever::serialize::SerializeOpts as XmlSerializeOpts;
@@ -568,7 +569,7 @@ pub fn get_attr_for_layout<'dom>(
 
 pub trait LayoutElementHelpers<'dom> {
     fn attrs(self) -> &'dom [LayoutDom<'dom, Attr>];
-    fn has_class_for_layout(self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool;
+    fn has_class_for_layout(self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool;
     fn get_classes_for_layout(self) -> Option<&'dom [Atom]>;
 
     fn synthesize_presentational_hints_for_legacy_attributes<V>(self, hints: &mut V)
@@ -616,7 +617,7 @@ impl<'dom> LayoutElementHelpers<'dom> for LayoutDom<'dom, Element> {
     }
 
     #[inline]
-    fn has_class_for_layout(self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class_for_layout(self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         get_attr_for_layout(self, &ns!(), &local_name!("class")).map_or(false, |attr| {
             attr.as_tokens()
                 .unwrap()
@@ -2851,6 +2852,7 @@ impl VirtualMethods for Element {
                                 &doc.base_url(),
                                 win.css_error_reporter(),
                                 doc.quirks_mode(),
+                                CssRuleType::Style,
                             )))
                         };
 
@@ -3135,16 +3137,16 @@ impl<'a> SelectorsElement for DomRoot<Element> {
 
     fn attr_matches(
         &self,
-        ns: &NamespaceConstraint<&Namespace>,
-        local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        ns: &NamespaceConstraint<&style::Namespace>,
+        local_name: &style::LocalName,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
                 .get_attribute(ns, local_name)
                 .map_or(false, |attr| attr.value().eval_selector(operation)),
             NamespaceConstraint::Any => self.attrs.borrow().iter().any(|attr| {
-                attr.local_name() == local_name && attr.value().eval_selector(operation)
+                *attr.local_name() == **local_name && attr.value().eval_selector(operation)
             }),
         }
     }
@@ -3240,23 +3242,23 @@ impl<'a> SelectorsElement for DomRoot<Element> {
         }
     }
 
-    fn has_id(&self, id: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_id(&self, id: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         self.id_attribute
             .borrow()
             .as_ref()
-            .map_or(false, |atom| case_sensitivity.eq_atom(id, atom))
+            .map_or(false, |atom| case_sensitivity.eq_atom(&*id, atom))
     }
 
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         None
     }
 
-    fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
-        Element::has_class(&**self, name, case_sensitivity)
+    fn has_class(&self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
+        Element::has_class(&**self, &name, case_sensitivity)
     }
 
     fn is_html_element_in_html_document(&self) -> bool {
diff --git a/components/script/dom/htmllinkelement.rs b/components/script/dom/htmllinkelement.rs
index d240b913a9e..30a45471203 100644
--- a/components/script/dom/htmllinkelement.rs
+++ b/components/script/dom/htmllinkelement.rs
@@ -39,7 +39,7 @@ use style::attr::AttrValue;
 use style::media_queries::MediaList;
 use style::parser::ParserContext as CssParserContext;
 use style::str::HTML_SPACE_CHARACTERS;
-use style::stylesheets::{CssRuleType, Stylesheet};
+use style::stylesheets::{CssRuleType, Origin, Stylesheet};
 use style_traits::ParsingMode;
 
 #[derive(Clone, Copy, JSTraceable, MallocSizeOf, PartialEq)]
@@ -310,7 +310,8 @@ impl HTMLLinkElement {
         // FIXME(emilio): This looks somewhat fishy, since we use the context
         // only to parse the media query list, CssRuleType::Media doesn't make
         // much sense.
-        let context = CssParserContext::new_for_cssom(
+        let context = CssParserContext::new(
+            Origin::Author,
             &doc_url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
diff --git a/components/script/dom/htmlstyleelement.rs b/components/script/dom/htmlstyleelement.rs
index 4e81837fc35..83d35fc78c8 100644
--- a/components/script/dom/htmlstyleelement.rs
+++ b/components/script/dom/htmlstyleelement.rs
@@ -96,7 +96,8 @@ impl HTMLStyleElement {
             .expect("Element.textContent must be a string");
         let url = window.get_url();
         let css_error_reporter = window.css_error_reporter();
-        let context = CssParserContext::new_for_cssom(
+        let context = CssParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
diff --git a/components/script/dom/medialist.rs b/components/script/dom/medialist.rs
index de0f61d0c00..772c508fc04 100644
--- a/components/script/dom/medialist.rs
+++ b/components/script/dom/medialist.rs
@@ -16,7 +16,7 @@ use style::media_queries::MediaList as StyleMediaList;
 use style::media_queries::MediaQuery;
 use style::parser::ParserContext;
 use style::shared_lock::{Locked, SharedRwLock};
-use style::stylesheets::CssRuleType;
+use style::stylesheets::{CssRuleType, Origin};
 use style_traits::{ParsingMode, ToCss};
 
 #[dom_struct]
@@ -81,7 +81,8 @@ impl MediaListMethods for MediaList {
         let window = global.as_window();
         let url = window.get_url();
         let quirks_mode = window.Document().quirks_mode();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
@@ -122,7 +123,8 @@ impl MediaListMethods for MediaList {
         let win = global.as_window();
         let url = win.get_url();
         let quirks_mode = win.Document().quirks_mode();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
@@ -159,7 +161,8 @@ impl MediaListMethods for MediaList {
         let win = global.as_window();
         let url = win.get_url();
         let quirks_mode = win.Document().quirks_mode();
-        let context = ParserContext::new_for_cssom(
+        let context = ParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 71ceb293664..7e36c8086fb 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -142,7 +142,7 @@ use style::properties::style_structs::Font;
 use style::properties::{PropertyId, ShorthandId};
 use style::selector_parser::PseudoElement;
 use style::str::HTML_SPACE_CHARACTERS;
-use style::stylesheets::CssRuleType;
+use style::stylesheets::{CssRuleType, Origin};
 use style_traits::{CSSPixel, DevicePixel, ParsingMode};
 use url::Position;
 use webrender_api::units::{DeviceIntPoint, DeviceIntSize, LayoutPixel};
@@ -1307,7 +1307,8 @@ impl WindowMethods for Window {
         let mut parser = Parser::new(&mut input);
         let url = self.get_url();
         let quirks_mode = self.Document().quirks_mode();
-        let context = CssParserContext::new_for_cssom(
+        let context = CssParserContext::new(
+            Origin::Author,
             &url,
             Some(CssRuleType::Media),
             ParsingMode::DEFAULT,
diff --git a/components/selectors/Cargo.toml b/components/selectors/Cargo.toml
index 0716da63752..f8e2b7ac538 100644
--- a/components/selectors/Cargo.toml
+++ b/components/selectors/Cargo.toml
@@ -19,7 +19,7 @@ bench = []
 
 [dependencies]
 bitflags = "1.0"
-cssparser = "0.27"
+cssparser = "0.28"
 derive_more = "0.99"
 fxhash = "0.2"
 log = "0.4"
diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index 244572b53bd..1d116063240 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -908,12 +908,7 @@ where
     let index = if let Some(i) = cache.as_mut().and_then(|c| c.lookup(element.opaque())) {
         i
     } else {
-        let i = nth_child_index(
-            element,
-            is_of_type,
-            is_from_end,
-            cache.as_deref_mut(),
-        );
+        let i = nth_child_index(element, is_of_type, is_from_end, cache.as_deref_mut());
         if let Some(c) = cache.as_mut() {
             c.insert(element.opaque(), i)
         }
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 70f66419250..a5fa010d50c 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -353,7 +353,12 @@ impl<Impl: SelectorImpl> SelectorList<Impl> {
     where
         P: Parser<'i, Impl = Impl>,
     {
-        Self::parse_with_state(parser, input, SelectorParsingState::empty(), ParseErrorRecovery::DiscardList)
+        Self::parse_with_state(
+            parser,
+            input,
+            SelectorParsingState::empty(),
+            ParseErrorRecovery::DiscardList,
+        )
     }
 
     #[inline]
@@ -387,7 +392,7 @@ impl<Impl: SelectorImpl> SelectorList<Impl> {
                     Ok(&Token::Comma) => break,
                     Ok(_) => {
                         debug_assert!(!was_ok, "Shouldn't have got a selector if getting here");
-                    }
+                    },
                 }
             }
         }
@@ -490,7 +495,9 @@ where
                 // :where and :is OR their selectors, so we can't put any hash
                 // in the filter if there's more than one selector, as that'd
                 // exclude elements that may match one of the other selectors.
-                if list.len() == 1 && !collect_ancestor_hashes(list[0].iter(), quirks_mode, hashes, len) {
+                if list.len() == 1 &&
+                    !collect_ancestor_hashes(list[0].iter(), quirks_mode, hashes, len)
+                {
                     return false;
                 }
                 continue;
@@ -1106,13 +1113,11 @@ impl<Impl: SelectorImpl> Component<Impl> {
             Component::NonTSPseudoClass(..) => true,
             Component::Negation(ref selectors) |
             Component::Is(ref selectors) |
-            Component::Where(ref selectors) => {
-                selectors.iter().all(|selector| {
-                    selector
-                        .iter_raw_match_order()
-                        .all(|c| c.maybe_allowed_after_pseudo_element())
-                })
-            },
+            Component::Where(ref selectors) => selectors.iter().all(|selector| {
+                selector
+                    .iter_raw_match_order()
+                    .all(|c| c.maybe_allowed_after_pseudo_element())
+            }),
             _ => false,
         }
     }
@@ -1130,13 +1135,11 @@ impl<Impl: SelectorImpl> Component<Impl> {
             *self
         );
         match *self {
-            Component::Negation(ref selectors) => {
-                !selectors.iter().all(|selector| {
-                    selector
-                        .iter_raw_match_order()
-                        .all(|c| c.matches_for_stateless_pseudo_element())
-                })
-            },
+            Component::Negation(ref selectors) => !selectors.iter().all(|selector| {
+                selector
+                    .iter_raw_match_order()
+                    .all(|c| c.matches_for_stateless_pseudo_element())
+            }),
             Component::Is(ref selectors) | Component::Where(ref selectors) => {
                 selectors.iter().any(|selector| {
                     selector
@@ -2114,8 +2117,10 @@ where
     let list = SelectorList::parse_with_state(
         parser,
         input,
-        state | SelectorParsingState::SKIP_DEFAULT_NAMESPACE | SelectorParsingState::DISALLOW_PSEUDOS,
-        ParseErrorRecovery::DiscardList
+        state |
+            SelectorParsingState::SKIP_DEFAULT_NAMESPACE |
+            SelectorParsingState::DISALLOW_PSEUDOS,
+        ParseErrorRecovery::DiscardList,
     )?;
 
     Ok(Component::Negation(list.0.into_vec().into_boxed_slice()))
@@ -2179,8 +2184,8 @@ where
                 //
                 //     (Similar quotes for :where() / :not())
                 //
-                let ignore_default_ns =
-                    state.intersects(SelectorParsingState::SKIP_DEFAULT_NAMESPACE) ||
+                let ignore_default_ns = state
+                    .intersects(SelectorParsingState::SKIP_DEFAULT_NAMESPACE) ||
                     matches!(
                         result,
                         SimpleSelectorParseResult::SimpleSelector(Component::Host(..))
@@ -2239,7 +2244,9 @@ where
     let inner = SelectorList::parse_with_state(
         parser,
         input,
-        state | SelectorParsingState::SKIP_DEFAULT_NAMESPACE | SelectorParsingState::DISALLOW_PSEUDOS,
+        state |
+            SelectorParsingState::SKIP_DEFAULT_NAMESPACE |
+            SelectorParsingState::DISALLOW_PSEUDOS,
         parser.is_and_where_error_recovery(),
     )?;
     Ok(component(inner.0.into_vec().into_boxed_slice()))
@@ -3038,13 +3045,12 @@ pub mod tests {
                 vec![
                     Component::DefaultNamespace(MATHML.into()),
                     Component::Negation(
-                        vec![
-                            Selector::from_vec(
-                                vec![Component::Class(DummyAtom::from("cl"))],
-                                specificity(0, 1, 0),
-                                Default::default(),
-                            )
-                        ].into_boxed_slice()
+                        vec![Selector::from_vec(
+                            vec![Component::Class(DummyAtom::from("cl"))],
+                            specificity(0, 1, 0),
+                            Default::default(),
+                        )]
+                        .into_boxed_slice()
                     ),
                 ],
                 specificity(0, 1, 0),
@@ -3057,16 +3063,14 @@ pub mod tests {
                 vec![
                     Component::DefaultNamespace(MATHML.into()),
                     Component::Negation(
-                        vec![
-                            Selector::from_vec(
-                                vec![
-                                    Component::DefaultNamespace(MATHML.into()),
-                                    Component::ExplicitUniversalType,
-                                ],
-                                specificity(0, 0, 0),
-                                Default::default(),
-                            )
-                        ]
+                        vec![Selector::from_vec(
+                            vec![
+                                Component::DefaultNamespace(MATHML.into()),
+                                Component::ExplicitUniversalType,
+                            ],
+                            specificity(0, 0, 0),
+                            Default::default(),
+                        )]
                         .into_boxed_slice(),
                     ),
                 ],
@@ -3080,19 +3084,17 @@ pub mod tests {
                 vec![
                     Component::DefaultNamespace(MATHML.into()),
                     Component::Negation(
-                        vec![
-                            Selector::from_vec(
-                                vec![
-                                    Component::DefaultNamespace(MATHML.into()),
-                                    Component::LocalName(LocalName {
-                                        name: DummyAtom::from("e"),
-                                        lower_name: DummyAtom::from("e"),
-                                    }),
-                                ],
-                                specificity(0, 0, 1),
-                                Default::default(),
-                            ),
-                        ]
+                        vec![Selector::from_vec(
+                            vec![
+                                Component::DefaultNamespace(MATHML.into()),
+                                Component::LocalName(LocalName {
+                                    name: DummyAtom::from("e"),
+                                    lower_name: DummyAtom::from("e"),
+                                }),
+                            ],
+                            specificity(0, 0, 1),
+                            Default::default(),
+                        ),]
                         .into_boxed_slice()
                     ),
                 ],
@@ -3196,15 +3198,12 @@ pub mod tests {
             parse_ns(":not(*)", &parser),
             Ok(SelectorList::from_vec(vec![Selector::from_vec(
                 vec![Component::Negation(
-                    vec![
-                        Selector::from_vec(
-                            vec![
-                                Component::ExplicitUniversalType
-                            ],
-                            specificity(0, 0, 0),
-                            Default::default(),
-                        )
-                    ].into_boxed_slice()
+                    vec![Selector::from_vec(
+                        vec![Component::ExplicitUniversalType],
+                        specificity(0, 0, 0),
+                        Default::default(),
+                    )]
+                    .into_boxed_slice()
                 )],
                 specificity(0, 0, 0),
                 Default::default(),
@@ -3214,16 +3213,14 @@ pub mod tests {
             parse_ns(":not(|*)", &parser),
             Ok(SelectorList::from_vec(vec![Selector::from_vec(
                 vec![Component::Negation(
-                    vec![
-                        Selector::from_vec(
-                            vec![
-                                Component::ExplicitNoNamespace,
-                                Component::ExplicitUniversalType,
-                            ],
-                            specificity(0, 0, 0),
-                            Default::default(),
-                        )
-                    ]
+                    vec![Selector::from_vec(
+                        vec![
+                            Component::ExplicitNoNamespace,
+                            Component::ExplicitUniversalType,
+                        ],
+                        specificity(0, 0, 0),
+                        Default::default(),
+                    )]
                     .into_boxed_slice(),
                 )],
                 specificity(0, 0, 0),
@@ -3236,15 +3233,12 @@ pub mod tests {
             parse_ns_expected(":not(*|*)", &parser, Some(":not(*)")),
             Ok(SelectorList::from_vec(vec![Selector::from_vec(
                 vec![Component::Negation(
-                    vec![
-                        Selector::from_vec(
-                            vec![
-                                Component::ExplicitUniversalType
-                            ],
-                            specificity(0, 0, 0),
-                            Default::default()
-                        )
-                    ].into_boxed_slice()
+                    vec![Selector::from_vec(
+                        vec![Component::ExplicitUniversalType],
+                        specificity(0, 0, 0),
+                        Default::default()
+                    )]
+                    .into_boxed_slice()
                 )],
                 specificity(0, 0, 0),
                 Default::default(),
diff --git a/components/style/attr.rs b/components/style/attr.rs
index 92ab7700fb8..05833fa08d8 100644
--- a/components/style/attr.rs
+++ b/components/style/attr.rs
@@ -12,6 +12,7 @@ use crate::str::str_join;
 use crate::str::{read_exponent, read_fraction, HTML_SPACE_CHARACTERS};
 use crate::str::{read_numbers, split_commas, split_html_space_chars};
 use crate::values::specified::Length;
+use crate::values::AtomString;
 use crate::{Atom, LocalName, Namespace, Prefix};
 use app_units::Au;
 use cssparser::{self, Color, RGBA};
@@ -354,7 +355,7 @@ impl AttrValue {
         }
     }
 
-    pub fn eval_selector(&self, selector: &AttrSelectorOperation<&String>) -> bool {
+    pub fn eval_selector(&self, selector: &AttrSelectorOperation<&AtomString>) -> bool {
         // FIXME(SimonSapin) this can be more efficient by matching on `(self, selector)` variants
         // and doing Atom comparisons instead of string comparisons where possible,
         // with SelectorImpl::AttrValue changed to Atom.
diff --git a/components/style/dom_apis.rs b/components/style/dom_apis.rs
index a6c50805cbb..6d19801cfc5 100644
--- a/components/style/dom_apis.rs
+++ b/components/style/dom_apis.rs
@@ -16,7 +16,6 @@ use selectors::matching::{self, MatchingContext, MatchingMode};
 use selectors::parser::{Combinator, Component, LocalName, SelectorImpl};
 use selectors::{Element, NthIndexCache, SelectorList};
 use smallvec::SmallVec;
-use std::borrow::Borrow;
 
 /// <https://dom.spec.whatwg.org/#dom-element-matches>
 pub fn element_matches<E>(
@@ -354,11 +353,14 @@ where
         ref name,
         ref lower_name,
     } = *local_name;
-    if element.is_html_element_in_html_document() {
-        element.local_name() == lower_name.borrow()
+
+    let chosen_name = if element.is_html_element_in_html_document() {
+        lower_name
     } else {
-        element.local_name() == name.borrow()
-    }
+        name
+    };
+
+    element.local_name() == &**chosen_name
 }
 
 /// Fast paths for querySelector with a single simple selector.
diff --git a/components/style/element_state.rs b/components/style/element_state.rs
index e05ff8778e7..0852b4574fa 100644
--- a/components/style/element_state.rs
+++ b/components/style/element_state.rs
@@ -128,7 +128,7 @@ bitflags! {
         /// https://html.spec.whatwg.org/multipage/#centered-alignment
         const IN_MODAL_DIALOG_STATE = 1 << 53;
 
-        /// https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees
+        /// https://html.spec.whatwg.org/multipage/#inert-subtrees
         const IN_MOZINERT_STATE = 1 << 54;
         /// State for the topmost dialog element in top layer
         const IN_TOPMOST_MODAL_DIALOG_STATE = 1 << 55;
diff --git a/components/style/gecko/media_features.rs b/components/style/gecko/media_features.rs
index 37d667896cc..bfc78b84b15 100644
--- a/components/style/gecko/media_features.rs
+++ b/components/style/gecko/media_features.rs
@@ -307,7 +307,7 @@ fn eval_prefers_reduced_motion(device: &Device, query_value: Option<PrefersReduc
 
 /// Possible values for prefers-contrast media query.
 /// https://drafts.csswg.org/mediaqueries-5/#prefers-contrast
-#[derive(Clone, Copy, Debug, FromPrimitive, PartialEq, Parse, ToCss)]
+#[derive(Clone, Copy, Debug, FromPrimitive, Parse, PartialEq, ToCss)]
 #[repr(u8)]
 pub enum PrefersContrast {
     /// More contrast is preferred. Corresponds to an accessibility theme
@@ -331,7 +331,7 @@ fn eval_prefers_contrast(device: &Device, query_value: Option<PrefersContrast>)
 
 /// Possible values for the forced-colors media query.
 /// https://drafts.csswg.org/mediaqueries-5/#forced-colors
-#[derive(Clone, Copy, Debug, FromPrimitive, PartialEq, Parse, ToCss)]
+#[derive(Clone, Copy, Debug, FromPrimitive, Parse, PartialEq, ToCss)]
 #[repr(u8)]
 pub enum ForcedColors {
     /// Page colors are not being forced.
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index a6cf017877d..cb040390cfe 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -147,6 +147,13 @@ impl PartialEq for WeakAtom {
     }
 }
 
+impl PartialEq<Atom> for WeakAtom {
+    #[inline]
+    fn eq(&self, other: &Atom) -> bool {
+        self == &**other
+    }
+}
+
 unsafe impl Send for Atom {}
 unsafe impl Sync for Atom {}
 unsafe impl Sync for WeakAtom {}
diff --git a/components/style/gecko_string_cache/namespace.rs b/components/style/gecko_string_cache/namespace.rs
index 1acf04c93ff..d9745b9e21f 100644
--- a/components/style/gecko_string_cache/namespace.rs
+++ b/components/style/gecko_string_cache/namespace.rs
@@ -47,7 +47,7 @@ impl PrecomputedHash for Namespace {
 }
 
 /// A Gecko WeakNamespace is a wrapped WeakAtom.
-#[derive(Hash, Deref)]
+#[derive(Deref, Hash)]
 pub struct WeakNamespace(WeakAtom);
 
 impl Deref for Namespace {
diff --git a/components/style/invalidation/stylesheets.rs b/components/style/invalidation/stylesheets.rs
index 9854387ccad..edecc3fc243 100644
--- a/components/style/invalidation/stylesheets.rs
+++ b/components/style/invalidation/stylesheets.rs
@@ -66,7 +66,7 @@ impl Invalidation {
 
 /// Whether we should invalidate just the element, or the whole subtree within
 /// it.
-#[derive(Copy, Clone, Debug, Eq, MallocSizeOf, Ord, PartialEq, PartialOrd)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Ord, PartialEq, PartialOrd)]
 enum InvalidationKind {
     None = 0,
     Element,
diff --git a/components/style/lib.rs b/components/style/lib.rs
index f1d36b2722c..a9853e4c823 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -139,13 +139,17 @@ pub type LocalName = crate::values::AtomIdent;
 pub use crate::gecko_string_cache::Namespace;
 
 #[cfg(feature = "servo")]
-pub use html5ever::LocalName;
+pub use servo_atoms::Atom;
+
 #[cfg(feature = "servo")]
-pub use html5ever::Namespace;
+#[allow(missing_docs)]
+pub type LocalName = crate::values::GenericAtomIdent<html5ever::LocalNameStaticSet>;
 #[cfg(feature = "servo")]
-pub use html5ever::Prefix;
+#[allow(missing_docs)]
+pub type Namespace = crate::values::GenericAtomIdent<html5ever::NamespaceStaticSet>;
 #[cfg(feature = "servo")]
-pub use servo_atoms::Atom;
+#[allow(missing_docs)]
+pub type Prefix = crate::values::GenericAtomIdent<html5ever::PrefixStaticSet>;
 
 pub use style_traits::arc_slice::ArcSlice;
 pub use style_traits::owned_slice::OwnedSlice;
diff --git a/components/style/macros.rs b/components/style/macros.rs
index e60be8efc5f..f5937d8b469 100644
--- a/components/style/macros.rs
+++ b/components/style/macros.rs
@@ -134,6 +134,23 @@ macro_rules! profiler_label {
     ($label_type:ident) => {};
 }
 
+#[cfg(feature = "servo")]
+macro_rules! local_name {
+    ($s:tt) => {
+        $crate::values::GenericAtomIdent(html5ever::local_name!($s))
+    };
+}
+
+#[cfg(feature = "servo")]
+macro_rules! ns {
+    () => {
+        $crate::values::GenericAtomIdent(html5ever::ns!())
+    };
+    ($s:tt) => {
+        $crate::values::GenericAtomIdent(html5ever::ns!($s))
+    };
+}
+
 #[cfg(feature = "gecko")]
 macro_rules! local_name {
     ($s:tt) => {
diff --git a/components/style/properties/build.py b/components/style/properties/build.py
index e74c9b9795f..97ad10408ea 100644
--- a/components/style/properties/build.py
+++ b/components/style/properties/build.py
@@ -111,7 +111,7 @@ def main():
                     p.name: {"pref": getattr(p, pref_attr)}
                     for prop in properties_list
                     if prop.enabled_in_content()
-                    for p in [prop] + prop.alias
+                    for p in [prop] + prop.aliases
                 }
                 for kind, properties_list in [
                     ("longhands", properties.longhands),
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index caa941df1ff..30eaac343ac 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -948,7 +948,8 @@
             input.parse_entirely(|input| parse_value(context, input)).map(|longhands| {
                 % for sub_property in shorthand.sub_properties:
                 % if sub_property.may_be_disabled_in(shorthand, engine):
-                if NonCustomPropertyId::from(LonghandId::${sub_property.camel_case}).allowed_in_ignoring_rule_type(context) {
+                if NonCustomPropertyId::from(LonghandId::${sub_property.camel_case})
+                    .allowed_in_ignoring_rule_type(context) {
                 % endif
                     declarations.push(PropertyDeclaration::${sub_property.camel_case}(
                         longhands.${sub_property.ident}
@@ -984,7 +985,10 @@
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Longhands, ParseError<'i>> {
-        let parse_one = |c: &ParserContext, input: &mut Parser<'i, 't>| -> Result<crate::properties::longhands::${to_rust_ident(first_property)}::SpecifiedValue, ParseError<'i>> {
+        let parse_one = |c: &ParserContext, input: &mut Parser<'i, 't>| -> Result<
+            crate::properties::longhands::${to_rust_ident(first_property)}::SpecifiedValue,
+            ParseError<'i>
+        > {
             ${parser_function}(c, input)
         };
 
@@ -1028,7 +1032,10 @@
             context: &ParserContext,
             input: &mut Parser<'i, 't>,
         ) -> Result<Longhands, ParseError<'i>> {
-            let rect = Rect::parse_with(context, input, |c, i| -> Result<crate::properties::longhands::${to_rust_ident(sub_property_pattern % "top")}::SpecifiedValue, ParseError<'i>> {
+            let rect = Rect::parse_with(context, input, |c, i| -> Result<
+                crate::properties::longhands::${to_rust_ident(sub_property_pattern % "top")}::SpecifiedValue,
+                ParseError<'i>
+            > {
             % if allow_quirks != "No":
                 ${parser_function}_quirky(c, i, specified::AllowQuirks::${allow_quirks})
             % else:
diff --git a/components/style/properties/longhands/inherited_ui.mako.rs b/components/style/properties/longhands/inherited_ui.mako.rs
index cb48acaa1fe..233ef365329 100644
--- a/components/style/properties/longhands/inherited_ui.mako.rs
+++ b/components/style/properties/longhands/inherited_ui.mako.rs
@@ -37,7 +37,7 @@ ${helpers.single_keyword(
     gecko_enum_prefix="StyleInert",
     animation_value_type="discrete",
     enabled_in="ua",
-    spec="Nonstandard (https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees)",
+    spec="Nonstandard (https://html.spec.whatwg.org/multipage/#inert-subtrees)",
 )}
 
 ${helpers.single_keyword(
diff --git a/components/style/properties/longhands/list.mako.rs b/components/style/properties/longhands/list.mako.rs
index b9a11a574f5..99d848d9db6 100644
--- a/components/style/properties/longhands/list.mako.rs
+++ b/components/style/properties/longhands/list.mako.rs
@@ -60,6 +60,7 @@ ${helpers.predefined_type(
     initial_specified_value="specified::Image::None",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image",
+    boxed=engine == "servo-2013",
     servo_restyle_damage="rebuild_and_reflow",
 )}
 
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index a3430526458..fc8ef438041 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -54,7 +54,8 @@ pub use self::cascade::*;
 
 <%!
     from collections import defaultdict
-    from data import Method, PropertyRestrictions, Keyword, to_rust_ident, to_camel_case, RULE_VALUES, SYSTEM_FONT_LONGHANDS
+    from data import Method, PropertyRestrictions, Keyword, to_rust_ident, \
+                     to_camel_case, RULE_VALUES, SYSTEM_FONT_LONGHANDS
     import os.path
 %>
 
@@ -1199,7 +1200,10 @@ impl LonghandId {
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<PropertyDeclaration, ParseError<'i>> {
-        type ParsePropertyFn = for<'i, 't> fn(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<PropertyDeclaration, ParseError<'i>>;
+        type ParsePropertyFn = for<'i, 't> fn(
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<PropertyDeclaration, ParseError<'i>>;
         static PARSE_PROPERTY: [ParsePropertyFn; ${len(data.longhands)}] = [
         % for property in data.longhands:
             longhands::${property.ident}::parse_declared,
diff --git a/components/style/servo/media_queries.rs b/components/style/servo/media_queries.rs
index 039bcf95e29..17949c723d0 100644
--- a/components/style/servo/media_queries.rs
+++ b/components/style/servo/media_queries.rs
@@ -4,6 +4,7 @@
 
 //! Servo's media-query device and expression representation.
 
+use crate::context::QuirksMode;
 use crate::custom_properties::CssEnvironment;
 use crate::media_queries::media_feature::{AllowsRanges, ParsingRequirements};
 use crate::media_queries::media_feature::{Evaluator, MediaFeatureDescription};
@@ -33,6 +34,9 @@ pub struct Device {
     viewport_size: Size2D<f32, CSSPixel>,
     /// The current device pixel ratio, from CSS pixels to device pixels.
     device_pixel_ratio: Scale<f32, CSSPixel, DevicePixel>,
+    /// The current quirks mode.
+    #[ignore_malloc_size_of = "Pure stack type"]
+    quirks_mode: QuirksMode,
 
     /// The font size of the root element
     /// This is set when computing the style of the root
@@ -60,6 +64,7 @@ impl Device {
     /// Trivially construct a new `Device`.
     pub fn new(
         media_type: MediaType,
+        quirks_mode: QuirksMode,
         viewport_size: Size2D<f32, CSSPixel>,
         device_pixel_ratio: Scale<f32, CSSPixel, DevicePixel>,
     ) -> Device {
@@ -67,6 +72,7 @@ impl Device {
             media_type,
             viewport_size,
             device_pixel_ratio,
+            quirks_mode,
             // FIXME(bz): Seems dubious?
             root_font_size: AtomicU32::new(FONT_MEDIUM_PX.to_bits()),
             used_root_font_size: AtomicBool::new(false),
@@ -101,6 +107,11 @@ impl Device {
             .store(size.px().to_bits(), Ordering::Relaxed)
     }
 
+    /// Get the quirks mode of the current device.
+    pub fn quirks_mode(&self) -> QuirksMode {
+        self.quirks_mode
+    }
+
     /// Sets the body text color for the "inherit color from body" quirk.
     ///
     /// <https://quirks.spec.whatwg.org/#the-tables-inherit-color-from-body-quirk>
diff --git a/components/style/servo/selector_parser.rs b/components/style/servo/selector_parser.rs
index 82722571c85..ce61c172553 100644
--- a/components/style/servo/selector_parser.rs
+++ b/components/style/servo/selector_parser.rs
@@ -15,6 +15,7 @@ use crate::properties::longhands::display::computed_value::T as Display;
 use crate::properties::{ComputedValues, PropertyFlags};
 use crate::selector_parser::AttrValue as SelectorAttrValue;
 use crate::selector_parser::{PseudoElementCascadeType, SelectorParser};
+use crate::values::{AtomIdent, AtomString};
 use crate::{Atom, CaseSensitivityExt, LocalName, Namespace, Prefix};
 use cssparser::{serialize_identifier, CowRcStr, Parser as CssParser, SourceLocation, ToCss};
 use fxhash::FxHashMap;
@@ -66,10 +67,6 @@ pub enum PseudoElement {
 /// The count of all pseudo-elements.
 pub const PSEUDO_COUNT: usize = PseudoElement::ServoInlineAbsolute as usize + 1;
 
-impl ::selectors::parser::PseudoElement for PseudoElement {
-    type Impl = SelectorImpl;
-}
-
 impl ToCss for PseudoElement {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result
     where
@@ -96,6 +93,10 @@ impl ToCss for PseudoElement {
     }
 }
 
+impl ::selectors::parser::PseudoElement for PseudoElement {
+    type Impl = SelectorImpl;
+}
+
 /// The number of eager pseudo-elements. Keep this in sync with cascade_type.
 pub const EAGER_PSEUDO_COUNT: usize = 3;
 
@@ -344,7 +345,6 @@ impl ToCss for NonTSPseudoClass {
             Fullscreen => ":fullscreen",
             Hover => ":hover",
             Indeterminate => ":indeterminate",
-            MozInert => ":-moz-inert",
             Link => ":link",
             PlaceholderShown => ":placeholder-shown",
             ReadWrite => ":read-write",
@@ -402,15 +402,13 @@ impl ::selectors::SelectorImpl for SelectorImpl {
     type NonTSPseudoClass = NonTSPseudoClass;
 
     type ExtraMatchingData = InvalidationMatchingData;
-    type AttrValue = String;
-    type Identifier = Atom;
-    type ClassName = Atom;
-    type PartName = Atom;
+    type AttrValue = AtomString;
+    type Identifier = AtomIdent;
     type LocalName = LocalName;
     type NamespacePrefix = Prefix;
     type NamespaceUrl = Namespace;
-    type BorrowedLocalName = LocalName;
-    type BorrowedNamespaceUrl = Namespace;
+    type BorrowedLocalName = html5ever::LocalName;
+    type BorrowedNamespaceUrl = html5ever::Namespace;
 }
 
 impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
@@ -434,7 +432,6 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
             "fullscreen" => Fullscreen,
             "hover" => Hover,
             "indeterminate" => Indeterminate,
-            "-moz-inert" => MozInert,
             "link" => Link,
             "placeholder-shown" => PlaceholderShown,
             "read-write" => ReadWrite,
@@ -697,15 +694,15 @@ impl ElementSnapshot for ServoElementSnapshot {
             .map(|v| v.as_atom())
     }
 
-    fn is_part(&self, _name: &Atom) -> bool {
+    fn is_part(&self, _name: &AtomIdent) -> bool {
         false
     }
 
-    fn imported_part(&self, _: &Atom) -> Option<Atom> {
+    fn imported_part(&self, _: &AtomIdent) -> Option<AtomIdent> {
         None
     }
 
-    fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
+    fn has_class(&self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
         self.get_attr(&ns!(), &local_name!("class"))
             .map_or(false, |v| {
                 v.as_tokens()
@@ -716,11 +713,11 @@ impl ElementSnapshot for ServoElementSnapshot {
 
     fn each_class<F>(&self, mut callback: F)
     where
-        F: FnMut(&Atom),
+        F: FnMut(&AtomIdent),
     {
         if let Some(v) = self.get_attr(&ns!(), &local_name!("class")) {
             for class in v.as_tokens() {
-                callback(class);
+                callback(AtomIdent::cast(class));
             }
         }
     }
@@ -728,7 +725,7 @@ impl ElementSnapshot for ServoElementSnapshot {
     fn lang_attr(&self) -> Option<SelectorAttrValue> {
         self.get_attr(&ns!(xml), &local_name!("lang"))
             .or_else(|| self.get_attr(&ns!(), &local_name!("lang")))
-            .map(|v| String::from(v as &str))
+            .map(|v| SelectorAttrValue::from(v as &str))
     }
 }
 
@@ -738,7 +735,7 @@ impl ServoElementSnapshot {
         &self,
         ns: &NamespaceConstraint<&Namespace>,
         local_name: &LocalName,
-        operation: &AttrSelectorOperation<&String>,
+        operation: &AttrSelectorOperation<&AtomString>,
     ) -> bool {
         match *ns {
             NamespaceConstraint::Specific(ref ns) => self
diff --git a/components/style/servo/url.rs b/components/style/servo/url.rs
index 8e011796e79..f4ae4e25edf 100644
--- a/components/style/servo/url.rs
+++ b/components/style/servo/url.rs
@@ -107,11 +107,17 @@ impl CssUrl {
     ///
     /// This is only for shape images and masks in Gecko, thus unimplemented for
     /// now so somebody notices when trying to do so.
-    pub fn parse_with_cors_anonymous<'i, 't>(
-        _context: &ParserContext,
-        _input: &mut Parser<'i, 't>,
+    pub fn parse_with_cors_mode<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+        cors_mode: CorsMode,
     ) -> Result<Self, ParseError<'i>> {
-        unimplemented!("Need to record somewhere that the request needs to be CORS-enabled")
+        let url = input.expect_url()?;
+        Ok(Self::parse_from_string(
+            url.as_ref().to_owned(),
+            context,
+            cors_mode,
+        ))
     }
 }
 
@@ -120,12 +126,7 @@ impl Parse for CssUrl {
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Self, ParseError<'i>> {
-        let url = input.expect_url()?;
-        Ok(Self::parse_from_string(
-            url.as_ref().to_owned(),
-            context,
-            CorsMode::None,
-        ))
+        Self::parse_with_cors_mode(context, input, CorsMode::None)
     }
 }
 
diff --git a/components/style/str.rs b/components/style/str.rs
index 9badcdf413c..c610b5241a7 100644
--- a/components/style/str.rs
+++ b/components/style/str.rs
@@ -179,3 +179,11 @@ pub type CssStringWriter = ::nsstring::nsACString;
 /// needs to allocate a temporary string.
 #[cfg(feature = "gecko")]
 pub type CssString = ::nsstring::nsCString;
+
+/// String. The comments for the Gecko types explain the need for this abstraction.
+#[cfg(feature = "servo")]
+pub type CssStringWriter = String;
+
+/// String. The comments for the Gecko types explain the need for this abstraction.
+#[cfg(feature = "servo")]
+pub type CssString = String;
diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index 13599c6630a..158be6d5dfb 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -9,7 +9,6 @@ use crate::computed_value_flags::ComputedValueFlags;
 use crate::dom::TElement;
 use crate::properties::longhands::display::computed_value::T as Display;
 use crate::properties::longhands::float::computed_value::T as Float;
-use crate::properties::longhands::overflow_x::computed_value::T as Overflow;
 use crate::properties::longhands::position::computed_value::T as Position;
 use crate::properties::{self, ComputedValues, StyleBuilder};
 
@@ -153,7 +152,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         }
     }
 
-    /// https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees
+    /// https://html.spec.whatwg.org/multipage/#inert-subtrees
     ///
     ///    If -moz-inert is applied then add:
     ///        -moz-user-focus: none;
@@ -168,6 +167,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
     ///
     /// NOTE: If this or the pointer-events tweak is removed, then
     /// minimal-xul.css and the scrollbar style caching need to be tweaked.
+    #[cfg(feature = "gecko")]
     fn adjust_for_inert(&mut self) {
         use crate::values::specified::ui::CursorKind;
         use crate::values::specified::ui::UserSelect;
@@ -529,6 +529,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
     /// parent, but we need to make sure it's still scrollable.
     #[cfg(feature = "gecko")]
     fn adjust_for_text_control_editing_root(&mut self) {
+        use crate::properties::longhands::overflow_x::computed_value::T as Overflow;
         use crate::selector_parser::PseudoElement;
 
         if self.style.pseudo != Some(&PseudoElement::MozTextControlEditingRoot) {
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index a07c51fe210..1b242547307 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -510,10 +510,11 @@ trivial_to_computed_value!(u16);
 trivial_to_computed_value!(u32);
 trivial_to_computed_value!(usize);
 trivial_to_computed_value!(Atom);
+trivial_to_computed_value!(crate::values::AtomIdent);
 #[cfg(feature = "servo")]
-trivial_to_computed_value!(html5ever::Namespace);
+trivial_to_computed_value!(crate::Namespace);
 #[cfg(feature = "servo")]
-trivial_to_computed_value!(html5ever::Prefix);
+trivial_to_computed_value!(crate::Prefix);
 trivial_to_computed_value!(String);
 trivial_to_computed_value!(Box<str>);
 trivial_to_computed_value!(crate::OwnedStr);
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index bb875b9f32e..d49a8a2b4de 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -117,7 +117,7 @@ pub use self::GenericCrossFadeElement as CrossFadeElement;
 pub use self::GenericCrossFadeImage as CrossFadeImage;
 
 /// https://drafts.csswg.org/css-images-4/#image-set-notation
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToResolvedValue, ToShmem, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue, ToShmem)]
 #[css(comma, function = "image-set")]
 #[repr(C)]
 pub struct GenericImageSet<Image, Resolution> {
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index 9587b52648d..79ec424ab3a 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -68,7 +68,7 @@ pub fn serialize_atom_identifier<Static, W>(
     dest: &mut W,
 ) -> fmt::Result
 where
-    Static: ::string_cache::StaticAtomSet,
+    Static: string_cache::StaticAtomSet,
     W: Write,
 {
     serialize_identifier(&ident, dest)
@@ -90,7 +90,7 @@ pub fn serialize_atom_name<Static, W>(
     dest: &mut W,
 ) -> fmt::Result
 where
-    Static: ::string_cache::StaticAtomSet,
+    Static: string_cache::StaticAtomSet,
     W: Write,
 {
     serialize_name(&ident, dest)
@@ -114,13 +114,27 @@ where
 )]
 pub struct AtomString(pub Atom);
 
+#[cfg(feature = "servo")]
+impl AsRef<str> for AtomString {
+    fn as_ref(&self) -> &str {
+        &*self.0
+    }
+}
+
 impl cssparser::ToCss for AtomString {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result
     where
         W: Write,
     {
-        self.0
-            .with_str(|s| cssparser::CssStringWriter::new(dest).write_str(s))
+        #[cfg(feature = "servo")]
+        {
+            cssparser::CssStringWriter::new(dest).write_str(self.as_ref())
+        }
+        #[cfg(feature = "gecko")]
+        {
+            self.0
+                .with_str(|s| cssparser::CssStringWriter::new(dest).write_str(s))
+        }
     }
 }
 
@@ -138,24 +152,138 @@ impl<'a> From<&'a str> for AtomString {
     }
 }
 
+/// A generic CSS `<ident>` stored as an `Atom`.
+#[cfg(feature = "servo")]
+#[repr(transparent)]
+#[derive(Deref)]
+pub struct GenericAtomIdent<Set>(pub string_cache::Atom<Set>)
+where
+    Set: string_cache::StaticAtomSet;
+
+/// A generic CSS `<ident>` stored as an `Atom`, for the default atom set.
+#[cfg(feature = "servo")]
+pub type AtomIdent = GenericAtomIdent<servo_atoms::AtomStaticSet>;
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> style_traits::SpecifiedValueInfo for GenericAtomIdent<Set> {}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> Default for GenericAtomIdent<Set> {
+    fn default() -> Self {
+        Self(string_cache::Atom::default())
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> std::fmt::Debug for GenericAtomIdent<Set> {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> std::hash::Hash for GenericAtomIdent<Set> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.0.hash(state)
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> Eq for GenericAtomIdent<Set> {}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> PartialEq for GenericAtomIdent<Set> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> Clone for GenericAtomIdent<Set> {
+    fn clone(&self) -> Self {
+        Self(self.0.clone())
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> to_shmem::ToShmem for GenericAtomIdent<Set> {
+    fn to_shmem(&self, builder: &mut to_shmem::SharedMemoryBuilder) -> to_shmem::Result<Self> {
+        use std::mem::ManuallyDrop;
+
+        let atom = self.0.to_shmem(builder)?;
+        Ok(ManuallyDrop::new(Self(ManuallyDrop::into_inner(atom))))
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> malloc_size_of::MallocSizeOf for GenericAtomIdent<Set> {
+    fn size_of(&self, ops: &mut malloc_size_of::MallocSizeOfOps) -> usize {
+        self.0.size_of(ops)
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> cssparser::ToCss for GenericAtomIdent<Set> {
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result
+    where
+        W: Write,
+    {
+        serialize_atom_identifier(&self.0, dest)
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> PrecomputedHash for GenericAtomIdent<Set> {
+    #[inline]
+    fn precomputed_hash(&self) -> u32 {
+        self.0.precomputed_hash()
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<'a, Set: string_cache::StaticAtomSet> From<&'a str> for GenericAtomIdent<Set> {
+    #[inline]
+    fn from(string: &str) -> Self {
+        Self(string_cache::Atom::from(string))
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> std::borrow::Borrow<string_cache::Atom<Set>>
+    for GenericAtomIdent<Set>
+{
+    #[inline]
+    fn borrow(&self) -> &string_cache::Atom<Set> {
+        &self.0
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<Set: string_cache::StaticAtomSet> GenericAtomIdent<Set> {
+    /// Constructs a new GenericAtomIdent.
+    #[inline]
+    pub fn new(atom: string_cache::Atom<Set>) -> Self {
+        Self(atom)
+    }
+
+    /// Cast an atom ref to an AtomIdent ref.
+    #[inline]
+    pub fn cast<'a>(atom: &'a string_cache::Atom<Set>) -> &'a Self {
+        let ptr = atom as *const _ as *const Self;
+        // safety: repr(transparent)
+        unsafe { &*ptr }
+    }
+}
+
 /// A CSS `<ident>` stored as an `Atom`.
+#[cfg(feature = "gecko")]
 #[repr(transparent)]
 #[derive(
-    Clone,
-    Debug,
-    Default,
-    Deref,
-    Eq,
-    Hash,
-    MallocSizeOf,
-    PartialEq,
-    SpecifiedValueInfo,
-    ToComputedValue,
-    ToResolvedValue,
-    ToShmem,
+    Clone, Debug, Default, Deref, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem,
 )]
 pub struct AtomIdent(pub Atom);
 
+#[cfg(feature = "gecko")]
 impl cssparser::ToCss for AtomIdent {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result
     where
@@ -165,6 +293,7 @@ impl cssparser::ToCss for AtomIdent {
     }
 }
 
+#[cfg(feature = "gecko")]
 impl PrecomputedHash for AtomIdent {
     #[inline]
     fn precomputed_hash(&self) -> u32 {
@@ -172,6 +301,7 @@ impl PrecomputedHash for AtomIdent {
     }
 }
 
+#[cfg(feature = "gecko")]
 impl<'a> From<&'a str> for AtomIdent {
     #[inline]
     fn from(string: &str) -> Self {
@@ -179,9 +309,15 @@ impl<'a> From<&'a str> for AtomIdent {
     }
 }
 
+#[cfg(feature = "gecko")]
 impl AtomIdent {
+    /// Constructs a new AtomIdent.
+    #[inline]
+    pub fn new(atom: Atom) -> Self {
+        Self(atom)
+    }
+
     /// Like `Atom::with` but for `AtomIdent`.
-    #[cfg(feature = "gecko")]
     pub unsafe fn with<F, R>(ptr: *const crate::gecko_bindings::structs::nsAtom, callback: F) -> R
     where
         F: FnOnce(&Self) -> R,
diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
index 45cc5cbd8cf..4ec84c2ae14 100644
--- a/components/style/values/resolved/mod.rs
+++ b/components/style/values/resolved/mod.rs
@@ -74,14 +74,15 @@ trivial_to_resolved_value!(Box<str>);
 trivial_to_resolved_value!(crate::OwnedStr);
 trivial_to_resolved_value!(cssparser::RGBA);
 trivial_to_resolved_value!(crate::Atom);
+trivial_to_resolved_value!(crate::values::AtomIdent);
 trivial_to_resolved_value!(app_units::Au);
 trivial_to_resolved_value!(computed::url::ComputedUrl);
 #[cfg(feature = "gecko")]
 trivial_to_resolved_value!(computed::url::ComputedImageUrl);
 #[cfg(feature = "servo")]
-trivial_to_resolved_value!(html5ever::Namespace);
+trivial_to_resolved_value!(crate::Namespace);
 #[cfg(feature = "servo")]
-trivial_to_resolved_value!(html5ever::Prefix);
+trivial_to_resolved_value!(crate::Prefix);
 trivial_to_resolved_value!(computed::LengthPercentage);
 trivial_to_resolved_value!(style_traits::values::specified::AllowedNumericType);
 
diff --git a/components/style/values/specified/image.rs b/components/style/values/specified/image.rs
index 51bacdf2ce5..3f150e74d1d 100644
--- a/components/style/values/specified/image.rs
+++ b/components/style/values/specified/image.rs
@@ -1144,15 +1144,6 @@ impl Parse for PaintWorklet {
 }
 
 impl MozImageRect {
-    #[cfg(not(feature = "gecko"))]
-    fn parse<'i, 't>(
-        _context: &ParserContext,
-        input: &mut Parser<'i, 't>,
-        _cors_mode: CorsMode,
-    ) -> Result<Self, ParseError<'i>> {
-        Err(input.new_error_for_next_token())
-    }
-
     #[cfg(feature = "gecko")]
     fn parse<'i, 't>(
         context: &ParserContext,
diff --git a/components/style/values/specified/resolution.rs b/components/style/values/specified/resolution.rs
index e8674cffaaa..5ed642f9818 100644
--- a/components/style/values/specified/resolution.rs
+++ b/components/style/values/specified/resolution.rs
@@ -12,7 +12,7 @@ use cssparser::{Parser, Token};
 use style_traits::{ParseError, StyleParseErrorKind};
 
 /// A specified resolution.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem, SpecifiedValueInfo)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum Resolution {
     /// Dots per inch.
     #[css(dimension)]
diff --git a/components/style/values/specified/table.rs b/components/style/values/specified/table.rs
index 79136b12ca1..81f3414e8f6 100644
--- a/components/style/values/specified/table.rs
+++ b/components/style/values/specified/table.rs
@@ -4,8 +4,6 @@
 
 //! Specified types for CSS values related to tables.
 
-use crate::parser::ParserContext;
-
 /// Specified values for the `caption-side` property.
 ///
 /// Note that despite having "physical" names, these are actually interpreted
@@ -15,7 +13,7 @@ use crate::parser::ParserContext;
 ///
 /// https://drafts.csswg.org/css-tables/#propdef-caption-side
 #[cfg(feature = "gecko")]
-fn caption_side_non_standard_enabled(_context: &ParserContext) -> bool {
+fn caption_side_non_standard_enabled(_: &crate::parser::ParserContext) -> bool {
     static_prefs::pref!("layout.css.caption-side-non-standard.enabled")
 }
 
diff --git a/components/style_traits/Cargo.toml b/components/style_traits/Cargo.toml
index 50e93ab25e6..02bee7d899c 100644
--- a/components/style_traits/Cargo.toml
+++ b/components/style_traits/Cargo.toml
@@ -16,7 +16,7 @@ gecko = []
 [dependencies]
 app_units = "0.7"
 bitflags = "1.0"
-cssparser = "0.27"
+cssparser = "0.28"
 euclid = "0.20"
 lazy_static = "1"
 malloc_size_of = { path = "../malloc_size_of" }
diff --git a/components/style_traits/values.rs b/components/style_traits/values.rs
index df33c949fb6..05ba0b5f2a5 100644
--- a/components/style_traits/values.rs
+++ b/components/style_traits/values.rs
@@ -118,6 +118,16 @@ where
     }
 }
 
+impl ToCss for () {
+    #[inline]
+    fn to_css<W>(&self, _: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: Write,
+    {
+        Ok(())
+    }
+}
+
 /// A writer tailored for serialising CSS.
 ///
 /// Coupled with SequenceWriter, this allows callers to transparently handle
diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
index 76be7671da3..6027d2670e6 100644
--- a/components/to_shmem/Cargo.toml
+++ b/components/to_shmem/Cargo.toml
@@ -14,7 +14,7 @@ servo = ["cssparser/serde", "string_cache"]
 gecko = []
 
 [dependencies]
-cssparser = "0.27"
+cssparser = "0.28"
 servo_arc = { path = "../servo_arc" }
 smallbitvec = "2.1.1"
 smallvec = "1.0"
diff --git a/components/url/lib.rs b/components/url/lib.rs
index d59d79e519a..944d02f29f7 100644
--- a/components/url/lib.rs
+++ b/components/url/lib.rs
@@ -103,6 +103,10 @@ impl ServoUrl {
         scheme == "about" || scheme == "blob" || scheme == "data"
     }
 
+    pub fn chrome_rules_enabled(&self) -> bool {
+        self.is_chrome()
+    }
+
     pub fn is_chrome(&self) -> bool {
         self.scheme() == "chrome"
     }
diff --git a/tests/unit/style/Cargo.toml b/tests/unit/style/Cargo.toml
index 2764c9d0408..51056e378f4 100644
--- a/tests/unit/style/Cargo.toml
+++ b/tests/unit/style/Cargo.toml
@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 app_units = "0.7"
-cssparser = "0.27"
+cssparser = "0.28"
 euclid = "0.20"
 html5ever = "0.25"
 rayon = "1"
diff --git a/tests/unit/style/custom_properties.rs b/tests/unit/style/custom_properties.rs
index 5bb0a800812..1e4ab0a7282 100644
--- a/tests/unit/style/custom_properties.rs
+++ b/tests/unit/style/custom_properties.rs
@@ -5,6 +5,7 @@
 use cssparser::{Parser, ParserInput};
 use euclid::{Scale, Size2D};
 use servo_arc::Arc;
+use style::context::QuirksMode;
 use style::custom_properties::{
     CustomPropertiesBuilder, CustomPropertiesMap, Name, SpecifiedValue,
 };
@@ -30,6 +31,7 @@ fn cascade(
 
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(800., 600.),
         Scale::new(1.0),
     );
diff --git a/tests/unit/style/parsing/selectors.rs b/tests/unit/style/parsing/selectors.rs
index 1ce7498caad..7aa77200732 100644
--- a/tests/unit/style/parsing/selectors.rs
+++ b/tests/unit/style/parsing/selectors.rs
@@ -12,7 +12,8 @@ fn parse_selector<'i, 't>(
     input: &mut Parser<'i, 't>,
 ) -> Result<SelectorList<SelectorImpl>, ParseError<'i>> {
     let mut ns = Namespaces::default();
-    ns.prefixes.insert("svg".into(), ns!(svg));
+    ns.prefixes
+        .insert("svg".into(), style::Namespace::new(ns!(svg)));
     let parser = SelectorParser {
         stylesheet_origin: Origin::UserAgent,
         namespaces: &ns,
diff --git a/tests/unit/style/stylist.rs b/tests/unit/style/stylist.rs
index 8836436c8be..31b7869a258 100644
--- a/tests/unit/style/stylist.rs
+++ b/tests/unit/style/stylist.rs
@@ -214,6 +214,7 @@ fn test_insert() {
 fn mock_stylist() -> Stylist {
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(0f32, 0f32),
         Scale::new(1.0),
     );
diff --git a/tests/unit/style/viewport.rs b/tests/unit/style/viewport.rs
index 445ec4bf8fd..c12939f8f34 100644
--- a/tests/unit/style/viewport.rs
+++ b/tests/unit/style/viewport.rs
@@ -113,6 +113,7 @@ macro_rules! viewport_length {
 fn empty_viewport_rule() {
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(800., 600.),
         Scale::new(1.0),
     );
@@ -140,6 +141,7 @@ macro_rules! assert_decl_eq {
 fn simple_viewport_rules() {
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(800., 600.),
         Scale::new(1.0),
     );
@@ -308,6 +310,7 @@ fn simple_meta_viewport_contents() {
 fn cascading_within_viewport_rule() {
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(800., 600.),
         Scale::new(1.0),
     );
@@ -448,6 +451,7 @@ fn multiple_stylesheets_cascading() {
     set_pref!(layout.viewport.enabled, true);
     let device = Device::new(
         MediaType::screen(),
+        QuirksMode::NoQuirks,
         Size2D::new(800., 600.),
         Scale::new(1.0),
     );
@@ -539,7 +543,12 @@ fn constrain_viewport() {
     }
 
     let initial_viewport = Size2D::new(800., 600.);
-    let device = Device::new(MediaType::screen(), initial_viewport, Scale::new(1.0));
+    let device = Device::new(
+        MediaType::screen(),
+        QuirksMode::NoQuirks,
+        initial_viewport,
+        Scale::new(1.0),
+    );
     let mut input = ParserInput::new("");
     assert_eq!(
         ViewportConstraints::maybe_new(&device, from_css!(input), QuirksMode::NoQuirks),
@@ -597,7 +606,12 @@ fn constrain_viewport() {
     );
 
     let initial_viewport = Size2D::new(200., 150.);
-    let device = Device::new(MediaType::screen(), initial_viewport, Scale::new(1.0));
+    let device = Device::new(
+        MediaType::screen(),
+        QuirksMode::NoQuirks,
+        initial_viewport,
+        Scale::new(1.0),
+    );
     let mut input = ParserInput::new("width: 320px auto");
     assert_eq!(
         ViewportConstraints::maybe_new(&device, from_css!(input), QuirksMode::NoQuirks),