Propagate quirks mode all the way to ParserContext

The quirks mode is still not properly propagated in geckolib.

39 files changed, 225 insertions, 100 deletions

diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index e69e55512d4..30d59180a3c 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -1589,7 +1589,8 @@ fn get_ua_stylesheets() -> Result<UserAgentStylesheets, &'static str> {
             MediaList::empty(),
             shared_lock.clone(),
             None,
-            &NullReporter))
+            &NullReporter,
+            QuirksMode::NoQuirks))
     }
 
     let shared_lock = SharedRwLock::new();
@@ -1602,7 +1603,7 @@ fn get_ua_stylesheets() -> Result<UserAgentStylesheets, &'static str> {
     for &(ref contents, ref url) in &opts::get().user_stylesheets {
         user_or_user_agent_stylesheets.push(Stylesheet::from_bytes(
             &contents, url.clone(), None, None, Origin::User, MediaList::empty(),
-            shared_lock.clone(), None, &RustLogReporter));
+            shared_lock.clone(), None, &RustLogReporter, QuirksMode::NoQuirks));
     }
 
     let quirks_mode_stylesheet = try!(parse_ua_stylesheet(&shared_lock, "quirks-mode.css"));
diff --git a/components/script/dom/css.rs b/components/script/dom/css.rs
index 0e4a7f85065..72cdbfa5be6 100644
--- a/components/script/dom/css.rs
+++ b/components/script/dom/css.rs
@@ -9,6 +9,7 @@ use dom::bindings::reflector::Reflector;
 use dom::bindings::str::DOMString;
 use dom::window::Window;
 use dom_struct::dom_struct;
+use style::context::QuirksMode;
 use style::parser::{LengthParsingMode, ParserContext};
 use style::stylesheets::CssRuleType;
 use style::supports::{Declaration, parse_condition_or_declaration};
@@ -31,7 +32,8 @@ impl CSS {
         let decl = Declaration { prop: property.into(), val: value.into() };
         let url = win.Document().url();
         let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Supports),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   QuirksMode::NoQuirks);
         decl.eval(&context)
     }
 
@@ -42,7 +44,8 @@ impl CSS {
         if let Ok(cond) = cond {
             let url = win.Document().url();
             let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Supports),
-                                                       LengthParsingMode::Default);
+                                                       LengthParsingMode::Default,
+                                                       QuirksMode::NoQuirks);
             cond.eval(&context)
         } else {
             false
diff --git a/components/script/dom/cssmediarule.rs b/components/script/dom/cssmediarule.rs
index aff12e2e2ad..45bf65b1adf 100644
--- a/components/script/dom/cssmediarule.rs
+++ b/components/script/dom/cssmediarule.rs
@@ -5,6 +5,7 @@
 use cssparser::Parser;
 use dom::bindings::codegen::Bindings::CSSMediaRuleBinding;
 use dom::bindings::codegen::Bindings::CSSMediaRuleBinding::CSSMediaRuleMethods;
+use dom::bindings::codegen::Bindings::WindowBinding::WindowBinding::WindowMethods;
 use dom::bindings::js::{MutNullableJS, Root};
 use dom::bindings::reflector::{DomObject, reflect_dom_object};
 use dom::bindings::str::DOMString;
@@ -72,8 +73,10 @@ impl CSSMediaRule {
         let global = self.global();
         let win = global.as_window();
         let url = win.get_url();
+        let quirks_mode = win.Document().quirks_mode();
         let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Media),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   quirks_mode);
         let new_medialist = parse_media_query_list(&context, &mut input);
         let mut guard = self.cssconditionrule.shared_lock().write();
 
diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index 22fd1194034..d0996f04567 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -256,9 +256,12 @@ impl CSSStyleDeclaration {
 
             // Step 6
             let window = self.owner.window();
+            let quirks_mode = window.Document().quirks_mode();
             let result =
                 parse_one_declaration(id, &value, &self.owner.base_url(),
-                                      window.css_error_reporter(), LengthParsingMode::Default);
+                                      window.css_error_reporter(),
+                                      LengthParsingMode::Default,
+                                      quirks_mode);
 
             // Step 7
             let parsed = match result {
@@ -434,11 +437,13 @@ impl CSSStyleDeclarationMethods for CSSStyleDeclaration {
             return Err(Error::NoModificationAllowed);
         }
 
+        let quirks_mode = window.Document().quirks_mode();
         self.owner.mutate_associated_block(|mut pdb, mut _changed| {
             // Step 3
             *pdb = parse_style_attribute(&value,
                                          &self.owner.base_url(),
-                                         window.css_error_reporter());
+                                         window.css_error_reporter(),
+                                         quirks_mode);
         });
 
         Ok(())
diff --git a/components/script/dom/csssupportsrule.rs b/components/script/dom/csssupportsrule.rs
index 3ac60a00e06..86aedf10864 100644
--- a/components/script/dom/csssupportsrule.rs
+++ b/components/script/dom/csssupportsrule.rs
@@ -61,8 +61,10 @@ impl CSSSupportsRule {
             let global = self.global();
             let win = global.as_window();
             let url = win.Document().url();
+            let quirks_mode = win.Document().quirks_mode();
             let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Supports),
-                                                       LengthParsingMode::Default);
+                                                       LengthParsingMode::Default,
+                                                       quirks_mode);
             let enabled = cond.eval(&context);
             let mut guard = self.cssconditionrule.shared_lock().write();
             let rule = self.supportsrule.write_with(&mut guard);
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 7b56b6c6e81..d6974fb9075 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -2196,7 +2196,8 @@ impl VirtualMethods for Element {
                             Arc::new(doc.style_shared_lock().wrap(parse_style_attribute(
                                 &attr.value(),
                                 &doc.base_url(),
-                                win.css_error_reporter())))
+                                win.css_error_reporter(),
+                                doc.quirks_mode())))
                         };
 
                         Some(block)
diff --git a/components/script/dom/htmllinkelement.rs b/components/script/dom/htmllinkelement.rs
index c0d0d12a775..bf36d28b29d 100644
--- a/components/script/dom/htmllinkelement.rs
+++ b/components/script/dom/htmllinkelement.rs
@@ -282,7 +282,8 @@ impl HTMLLinkElement {
         let win = document.window();
         let doc_url = document.url();
         let context = CssParserContext::new_for_cssom(&doc_url, win.css_error_reporter(), Some(CssRuleType::Media),
-                                                      LengthParsingMode::Default);
+                                                      LengthParsingMode::Default,
+                                                      document.quirks_mode());
         let media = parse_media_query_list(&context, &mut css_parser);
 
         let im_attribute = element.get_attribute(&ns!(), &local_name!("integrity"));
diff --git a/components/script/dom/htmlmetaelement.rs b/components/script/dom/htmlmetaelement.rs
index 3c4e817a132..62d7215e3df 100644
--- a/components/script/dom/htmlmetaelement.rs
+++ b/components/script/dom/htmlmetaelement.rs
@@ -113,6 +113,7 @@ impl HTMLMetaElement {
                         // force all styles to be recomputed.
                         dirty_on_viewport_size_change: AtomicBool::new(false),
                         disabled: AtomicBool::new(false),
+                        quirks_mode: document.quirks_mode(),
                     }));
                     let doc = document_from_node(self);
                     doc.invalidate_stylesheets();
diff --git a/components/script/dom/htmlstyleelement.rs b/components/script/dom/htmlstyleelement.rs
index 0c026fcfe9a..8905c3baa65 100644
--- a/components/script/dom/htmlstyleelement.rs
+++ b/components/script/dom/htmlstyleelement.rs
@@ -76,6 +76,7 @@ impl HTMLStyleElement {
         assert!(node.is_in_doc());
 
         let win = window_from_node(node);
+        let doc = document_from_node(self);
 
         let mq_attribute = element.get_attribute(&ns!(), &local_name!("media"));
         let mq_str = match mq_attribute {
@@ -88,7 +89,8 @@ impl HTMLStyleElement {
         let context = CssParserContext::new_for_cssom(&url,
                                                       win.css_error_reporter(),
                                                       Some(CssRuleType::Media),
-                                                      LengthParsingMode::Default);
+                                                      LengthParsingMode::Default,
+                                                      doc.quirks_mode());
         let shared_lock = node.owner_doc().style_shared_lock().clone();
         let mq = Arc::new(shared_lock.wrap(
                     parse_media_query_list(&context, &mut CssParser::new(&mq_str))));
@@ -96,6 +98,7 @@ impl HTMLStyleElement {
         let sheet = Stylesheet::from_str(&data, win.get_url(), Origin::Author, mq,
                                          shared_lock, Some(&loader),
                                          win.css_error_reporter(),
+                                         doc.quirks_mode(),
                                          self.line_number);
 
         let sheet = Arc::new(sheet);
@@ -107,7 +110,6 @@ impl HTMLStyleElement {
 
         win.layout_chan().send(Msg::AddStylesheet(sheet.clone())).unwrap();
         *self.stylesheet.borrow_mut() = Some(sheet);
-        let doc = document_from_node(self);
         doc.invalidate_stylesheets();
     }
 
diff --git a/components/script/dom/medialist.rs b/components/script/dom/medialist.rs
index 881c17966da..f2a2299d169 100644
--- a/components/script/dom/medialist.rs
+++ b/components/script/dom/medialist.rs
@@ -5,6 +5,7 @@
 use cssparser::Parser;
 use dom::bindings::codegen::Bindings::MediaListBinding;
 use dom::bindings::codegen::Bindings::MediaListBinding::MediaListMethods;
+use dom::bindings::codegen::Bindings::WindowBinding::WindowBinding::WindowMethods;
 use dom::bindings::js::{JS, Root};
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::str::DOMString;
@@ -74,8 +75,10 @@ impl MediaListMethods for MediaList {
         let global = self.global();
         let win = global.as_window();
         let url = win.get_url();
+        let quirks_mode = win.Document().quirks_mode();
         let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Media),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   quirks_mode);
         *media_queries = parse_media_query_list(&context, &mut parser);
     }
 
@@ -108,8 +111,10 @@ impl MediaListMethods for MediaList {
         let global = self.global();
         let win = global.as_window();
         let url = win.get_url();
+        let quirks_mode = win.Document().quirks_mode();
         let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Media),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   quirks_mode);
         let m = MediaQuery::parse(&context, &mut parser);
         // Step 2
         if let Err(_) = m {
@@ -134,8 +139,10 @@ impl MediaListMethods for MediaList {
         let global = self.global();
         let win = global.as_window();
         let url = win.get_url();
+        let quirks_mode = win.Document().quirks_mode();
         let context = ParserContext::new_for_cssom(&url, win.css_error_reporter(), Some(CssRuleType::Media),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   quirks_mode);
         let m = MediaQuery::parse(&context, &mut parser);
         // Step 2
         if let Err(_) = m {
diff --git a/components/script/dom/mediaquerylist.rs b/components/script/dom/mediaquerylist.rs
index dafc7602794..b25e041f4ef 100644
--- a/components/script/dom/mediaquerylist.rs
+++ b/components/script/dom/mediaquerylist.rs
@@ -77,7 +77,7 @@ impl MediaQueryList {
         if let Some(window_size) = self.document.window().window_size() {
             let viewport_size = window_size.initial_viewport;
             let device = Device::new(MediaType::Screen, viewport_size);
-            self.media_query_list.evaluate(&device)
+            self.media_query_list.evaluate(&device, self.document.quirks_mode())
         } else {
             false
         }
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index eaba1ded928..6b8857b81b1 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -976,8 +976,10 @@ impl WindowMethods for Window {
     fn MatchMedia(&self, query: DOMString) -> Root<MediaQueryList> {
         let mut parser = Parser::new(&query);
         let url = self.get_url();
+        let quirks_mode = self.Document().quirks_mode();
         let context = CssParserContext::new_for_cssom(&url, self.css_error_reporter(), Some(CssRuleType::Media),
-                                                      LengthParsingMode::Default);
+                                                      LengthParsingMode::Default,
+                                                      quirks_mode);
         let media_query_list = media_queries::parse_media_query_list(&context, &mut parser);
         let document = self.Document();
         let mql = MediaQueryList::new(&document, media_query_list);
diff --git a/components/script/stylesheet_loader.rs b/components/script/stylesheet_loader.rs
index a859e798818..14b8c385e39 100644
--- a/components/script/stylesheet_loader.rs
+++ b/components/script/stylesheet_loader.rs
@@ -144,7 +144,8 @@ impl FetchResponseListener for StylesheetContext {
                                                             media.take().unwrap(),
                                                             shared_lock,
                                                             Some(&loader),
-                                                            win.css_error_reporter()));
+                                                            win.css_error_reporter(),
+                                                            document.quirks_mode()));
 
                         if link.is_alternate() {
                             sheet.set_disabled(true);
diff --git a/components/style/animation.rs b/components/style/animation.rs
index 16c7dab364d..01dcc850fc7 100644
--- a/components/style/animation.rs
+++ b/components/style/animation.rs
@@ -451,7 +451,8 @@ fn compute_style_for_animation_step(context: &SharedStyleContext,
                                                /* cascade_info = */ None,
                                                &*context.error_reporter,
                                                font_metrics_provider,
-                                               CascadeFlags::empty());
+                                               CascadeFlags::empty(),
+                                               context.quirks_mode);
             computed
         }
     }
diff --git a/components/style/encoding_support.rs b/components/style/encoding_support.rs
index b61c743051f..2775de54893 100644
--- a/components/style/encoding_support.rs
+++ b/components/style/encoding_support.rs
@@ -6,6 +6,7 @@
 
 extern crate encoding;
 
+use context::QuirksMode;
 use cssparser::{stylesheet_encoding, EncodingSupport};
 use error_reporting::ParseErrorReporter;
 use media_queries::MediaList;
@@ -56,7 +57,8 @@ impl Stylesheet {
                       media: MediaList,
                       shared_lock: SharedRwLock,
                       stylesheet_loader: Option<&StylesheetLoader>,
-                      error_reporter: &ParseErrorReporter)
+                      error_reporter: &ParseErrorReporter,
+                      quirks_mode: QuirksMode)
                       -> Stylesheet {
         let (string, _) = decode_stylesheet_bytes(
             bytes, protocol_encoding_label, environment_encoding);
@@ -67,6 +69,7 @@ impl Stylesheet {
                              shared_lock,
                              stylesheet_loader,
                              error_reporter,
+                             quirks_mode,
                              0u64)
     }
 
diff --git a/components/style/gecko/media_queries.rs b/components/style/gecko/media_queries.rs
index 4aff56ee8d5..8aa3b2da396 100644
--- a/components/style/gecko/media_queries.rs
+++ b/components/style/gecko/media_queries.rs
@@ -5,6 +5,7 @@
 //! Gecko's media-query device and expression representation.
 
 use app_units::Au;
+use context::QuirksMode;
 use cssparser::{CssStringWriter, Parser, Token};
 use euclid::Size2D;
 use font_metrics::get_metrics_provider_for_product;
@@ -521,7 +522,7 @@ impl Expression {
     }
 
     /// Returns whether this media query evaluates to true for the given device.
-    pub fn matches(&self, device: &Device) -> bool {
+    pub fn matches(&self, device: &Device, quirks_mode: QuirksMode) -> bool {
         let mut css_value = nsCSSValue::null();
         unsafe {
             (self.feature.mGetter.unwrap())(device.pres_context,
@@ -534,12 +535,13 @@ impl Expression {
             None => return false,
         };
 
-        self.evaluate_against(device, &value)
+        self.evaluate_against(device, &value, quirks_mode)
     }
 
     fn evaluate_against(&self,
                         device: &Device,
-                        actual_value: &MediaExpressionValue)
+                        actual_value: &MediaExpressionValue,
+                        quirks_mode: QuirksMode)
                         -> bool {
         use self::MediaExpressionValue::*;
         use std::cmp::Ordering;
@@ -564,6 +566,8 @@ impl Expression {
             style: default_values.clone(),
             font_metrics_provider: &provider,
             in_media_query: true,
+            // TODO: pass the correct value here.
+            quirks_mode: quirks_mode,
         };
 
         let required_value = match self.value {
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 948a87d4cf6..7ec5a4cce72 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -16,7 +16,7 @@
 
 use app_units::Au;
 use atomic_refcell::AtomicRefCell;
-use context::{SharedStyleContext, UpdateAnimationsTasks};
+use context::{QuirksMode, SharedStyleContext, UpdateAnimationsTasks};
 use data::ElementData;
 use dom::{self, AnimationRules, DescendantsBit, LayoutIterator, NodeInfo, TElement, TNode, UnsafeNode};
 use dom::{OpaqueNode, PresentationalHintsSynthetizer};
@@ -324,7 +324,7 @@ impl<'le> GeckoElement<'le> {
     /// Parse the style attribute of an element.
     pub fn parse_style_attribute(value: &str,
                                  url_data: &UrlExtraData) -> PropertyDeclarationBlock {
-        parse_style_attribute(value, url_data, &RustLogReporter)
+        parse_style_attribute(value, url_data, &RustLogReporter, QuirksMode::NoQuirks)
     }
 
     fn flags(&self) -> u32 {
diff --git a/components/style/keyframes.rs b/components/style/keyframes.rs
index fb8290fedf4..8113c06bb6c 100644
--- a/components/style/keyframes.rs
+++ b/components/style/keyframes.rs
@@ -131,7 +131,8 @@ impl Keyframe {
                                          &parent_stylesheet.url_data,
                                          &error_reporter,
                                          Some(CssRuleType::Keyframe),
-                                         LengthParsingMode::Default);
+                                         LengthParsingMode::Default,
+                                         parent_stylesheet.quirks_mode);
         let mut input = Parser::new(css);
 
         let mut rule_parser = KeyframeListParser {
diff --git a/components/style/matching.rs b/components/style/matching.rs
index 201f6c50878..01b25bcccf9 100644
--- a/components/style/matching.rs
+++ b/components/style/matching.rs
@@ -453,7 +453,8 @@ trait PrivateMatchMethods: TElement {
                              Some(&mut cascade_info),
                              &*shared_context.error_reporter,
                              font_metrics_provider,
-                             cascade_flags));
+                             cascade_flags,
+                             shared_context.quirks_mode));
 
         cascade_info.finish(&self.as_node());
         values
diff --git a/components/style/media_queries.rs b/components/style/media_queries.rs
index 10a29509bd1..4f1b3d68a12 100644
--- a/components/style/media_queries.rs
+++ b/components/style/media_queries.rs
@@ -7,6 +7,7 @@
 //! [mq]: https://drafts.csswg.org/mediaqueries/
 
 use Atom;
+use context::QuirksMode;
 use cssparser::{Delimiter, Parser, Token};
 use parser::ParserContext;
 use serialize_comma_separated_list;
@@ -280,7 +281,7 @@ pub fn parse_media_query_list(context: &ParserContext, input: &mut Parser) -> Me
 
 impl MediaList {
     /// Evaluate a whole `MediaList` against `Device`.
-    pub fn evaluate(&self, device: &Device) -> bool {
+    pub fn evaluate(&self, device: &Device, quirks_mode: QuirksMode) -> bool {
         // Check if it is an empty media query list or any queries match (OR condition)
         // https://drafts.csswg.org/mediaqueries-4/#mq-list
         self.media_queries.is_empty() || self.media_queries.iter().any(|mq| {
@@ -290,7 +291,7 @@ impl MediaList {
             let query_match =
                 media_match &&
                 mq.expressions.iter()
-                    .all(|expression| expression.matches(&device));
+                    .all(|expression| expression.matches(&device, quirks_mode));
 
             // Apply the logical NOT qualifier to the result
             match mq.qualifier {
diff --git a/components/style/parser.rs b/components/style/parser.rs
index b82d21ace4f..bac1252228a 100644
--- a/components/style/parser.rs
+++ b/components/style/parser.rs
@@ -6,6 +6,7 @@
 
 #![deny(missing_docs)]
 
+use context::QuirksMode;
 use cssparser::{Parser, SourcePosition, UnicodeRange};
 use error_reporting::ParseErrorReporter;
 use style_traits::OneOrMoreCommaSeparated;
@@ -44,6 +45,8 @@ pub struct ParserContext<'a> {
     pub line_number_offset: u64,
     /// The mode to use when parsing lengths.
     pub length_parsing_mode: LengthParsingMode,
+    /// The quirks mode of this stylesheet.
+    pub quirks_mode: QuirksMode,
 }
 
 impl<'a> ParserContext<'a> {
@@ -52,7 +55,8 @@ impl<'a> ParserContext<'a> {
                url_data: &'a UrlExtraData,
                error_reporter: &'a ParseErrorReporter,
                rule_type: Option<CssRuleType>,
-               length_parsing_mode: LengthParsingMode)
+               length_parsing_mode: LengthParsingMode,
+               quirks_mode: QuirksMode)
                -> ParserContext<'a> {
         ParserContext {
             stylesheet_origin: stylesheet_origin,
@@ -61,6 +65,7 @@ impl<'a> ParserContext<'a> {
             rule_type: rule_type,
             line_number_offset: 0u64,
             length_parsing_mode: length_parsing_mode,
+            quirks_mode: quirks_mode,
         }
     }
 
@@ -68,9 +73,10 @@ impl<'a> ParserContext<'a> {
     pub fn new_for_cssom(url_data: &'a UrlExtraData,
                          error_reporter: &'a ParseErrorReporter,
                          rule_type: Option<CssRuleType>,
-                         length_parsing_mode: LengthParsingMode)
+                         length_parsing_mode: LengthParsingMode,
+                         quirks_mode: QuirksMode)
                          -> ParserContext<'a> {
-        Self::new(Origin::Author, url_data, error_reporter, rule_type, length_parsing_mode)
+        Self::new(Origin::Author, url_data, error_reporter, rule_type, length_parsing_mode, quirks_mode)
     }
 
     /// Create a parser context based on a previous context, but with a modified rule type.
@@ -84,6 +90,7 @@ impl<'a> ParserContext<'a> {
             rule_type: rule_type,
             line_number_offset: context.line_number_offset,
             length_parsing_mode: context.length_parsing_mode,
+            quirks_mode: context.quirks_mode,
         }
     }
 
@@ -92,7 +99,8 @@ impl<'a> ParserContext<'a> {
                                        url_data: &'a UrlExtraData,
                                        error_reporter: &'a ParseErrorReporter,
                                        line_number_offset: u64,
-                                       length_parsing_mode: LengthParsingMode)
+                                       length_parsing_mode: LengthParsingMode,
+                                       quirks_mode: QuirksMode)
                                        -> ParserContext<'a> {
         ParserContext {
             stylesheet_origin: stylesheet_origin,
@@ -101,6 +109,7 @@ impl<'a> ParserContext<'a> {
             rule_type: None,
             line_number_offset: line_number_offset,
             length_parsing_mode: length_parsing_mode,
+            quirks_mode: quirks_mode,
         }
     }
 
diff --git a/components/style/properties/declaration_block.rs b/components/style/properties/declaration_block.rs
index d652ab21c96..7b53a49626a 100644
--- a/components/style/properties/declaration_block.rs
+++ b/components/style/properties/declaration_block.rs
@@ -6,6 +6,7 @@
 
 #![deny(missing_docs)]
 
+use context::QuirksMode;
 use cssparser::{DeclarationListParser, parse_important};
 use cssparser::{Parser, AtRuleParser, DeclarationParser, Delimiter};
 use error_reporting::ParseErrorReporter;
@@ -641,13 +642,15 @@ pub fn append_serialization<'a, W, I, N>(dest: &mut W,
 /// shared between Servo and Gecko.
 pub fn parse_style_attribute(input: &str,
                              url_data: &UrlExtraData,
-                             error_reporter: &ParseErrorReporter)
+                             error_reporter: &ParseErrorReporter,
+                             quirks_mode: QuirksMode)
                              -> PropertyDeclarationBlock {
     let context = ParserContext::new(Origin::Author,
                                      url_data,
                                      error_reporter,
                                      Some(CssRuleType::Style),
-                                     LengthParsingMode::Default);
+                                     LengthParsingMode::Default,
+                                     quirks_mode);
     parse_property_declaration_list(&context, &mut Parser::new(input))
 }
 
@@ -660,13 +663,15 @@ pub fn parse_one_declaration(id: PropertyId,
                              input: &str,
                              url_data: &UrlExtraData,
                              error_reporter: &ParseErrorReporter,
-                             length_parsing_mode: LengthParsingMode)
+                             length_parsing_mode: LengthParsingMode,
+                             quirks_mode: QuirksMode)
                              -> Result<ParsedDeclaration, ()> {
     let context = ParserContext::new(Origin::Author,
                                      url_data,
                                      error_reporter,
                                      Some(CssRuleType::Style),
-                                     length_parsing_mode);
+                                     length_parsing_mode,
+                                     quirks_mode);
     Parser::new(input).parse_entirely(|parser| {
         ParsedDeclaration::parse(id, &context, parser)
             .map_err(|_| ())
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 5d13f91e282..2505d1f82d5 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -277,6 +277,7 @@
             % if not property.derived_from:
                 {
                     let custom_props = context.style().custom_properties();
+                    let quirks_mode = context.quirks_mode;
                     ::properties::substitute_variables_${property.ident}(
                         &declared_value, &custom_props,
                     |value| {
@@ -349,7 +350,7 @@
                                 }
                             }
                         }
-                    }, error_reporter);
+                    }, error_reporter, quirks_mode);
                 }
 
                 % if property.custom_cascade:
diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs
index cd384da294a..6e8cefc74c5 100644
--- a/components/style/properties/helpers/animated_properties.mako.rs
+++ b/components/style/properties/helpers/animated_properties.mako.rs
@@ -515,6 +515,7 @@ impl AnimationValue {
                     % if prop.animatable:
                     LonghandId::${prop.camel_case} => {
                         let mut result = None;
+                        let quirks_mode = context.quirks_mode;
                         ::properties::substitute_variables_${prop.ident}_slow(
                             &variables.css,
                             variables.first_token_type,
@@ -533,7 +534,8 @@ impl AnimationValue {
                                 };
                                 result = AnimationValue::from_declaration(&declaration, context, initial);
                             },
-                            &reporter);
+                            &reporter,
+                            quirks_mode);
                         result
                     },
                     % else:
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index fa6ed21a33b..366ae8af469 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -21,6 +21,7 @@ use cssparser::{Parser, TokenSerializationType};
 use error_reporting::ParseErrorReporter;
 #[cfg(feature = "servo")] use euclid::side_offsets::SideOffsets2D;
 use computed_values;
+use context::QuirksMode;
 use font_metrics::FontMetricsProvider;
 #[cfg(feature = "gecko")] use gecko_bindings::bindings;
 #[cfg(feature = "gecko")] use gecko_bindings::structs::{self, nsCSSPropertyID};
@@ -327,7 +328,8 @@ impl PropertyDeclarationIdSet {
             % endif
             custom_properties: &Option<Arc<::custom_properties::ComputedValuesMap>>,
             f: F,
-            error_reporter: &ParseErrorReporter)
+            error_reporter: &ParseErrorReporter,
+            quirks_mode: QuirksMode)
             % if property.boxed:
                 where F: FnOnce(&DeclaredValue<Box<longhands::${property.ident}::SpecifiedValue>>)
             % else:
@@ -341,7 +343,8 @@ impl PropertyDeclarationIdSet {
                                                             with_variables.from_shorthand,
                                                             custom_properties,
                                                             f,
-                                                            error_reporter);
+                                                            error_reporter,
+                                                            quirks_mode);
             } else {
                 f(value);
             }
@@ -356,7 +359,8 @@ impl PropertyDeclarationIdSet {
                 from_shorthand: Option<ShorthandId>,
                 custom_properties: &Option<Arc<::custom_properties::ComputedValuesMap>>,
                 f: F,
-                error_reporter: &ParseErrorReporter)
+                error_reporter: &ParseErrorReporter,
+                quirks_mode: QuirksMode)
                 % if property.boxed:
                     where F: FnOnce(&DeclaredValue<Box<longhands::${property.ident}::SpecifiedValue>>)
                 % else:
@@ -374,7 +378,8 @@ impl PropertyDeclarationIdSet {
                                                      url_data,
                                                      error_reporter,
                                                      None,
-                                                     LengthParsingMode::Default);
+                                                     LengthParsingMode::Default,
+                                                     quirks_mode);
                     Parser::new(&css).parse_entirely(|input| {
                         match from_shorthand {
                             None => {
@@ -2114,7 +2119,8 @@ pub fn cascade(device: &Device,
                cascade_info: Option<<&mut CascadeInfo>,
                error_reporter: &ParseErrorReporter,
                font_metrics_provider: &FontMetricsProvider,
-               flags: CascadeFlags)
+               flags: CascadeFlags,
+               quirks_mode: QuirksMode)
                -> ComputedValues {
     debug_assert_eq!(parent_style.is_some(), layout_parent_style.is_some());
     let (is_root_element, inherited_style, layout_parent_style) = match parent_style {
@@ -2159,7 +2165,8 @@ pub fn cascade(device: &Device,
                        cascade_info,
                        error_reporter,
                        font_metrics_provider,
-                       flags)
+                       flags,
+                       quirks_mode)
 }
 
 /// NOTE: This function expects the declaration with more priority to appear
@@ -2173,7 +2180,8 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
                                     mut cascade_info: Option<<&mut CascadeInfo>,
                                     error_reporter: &ParseErrorReporter,
                                     font_metrics_provider: &FontMetricsProvider,
-                                    flags: CascadeFlags)
+                                    flags: CascadeFlags,
+                                    quirks_mode: QuirksMode)
                                     -> ComputedValues
     where F: Fn() -> I,
           I: Iterator<Item = &'a PropertyDeclaration>,
@@ -2226,6 +2234,7 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
         style: starting_style,
         font_metrics_provider: font_metrics_provider,
         in_media_query: false,
+        quirks_mode: quirks_mode,
     };
 
     // Set computed values, overwriting earlier declarations for the same
diff --git a/components/style/servo/media_queries.rs b/components/style/servo/media_queries.rs
index c2ff1cb828d..4756d5bb705 100644
--- a/components/style/servo/media_queries.rs
+++ b/components/style/servo/media_queries.rs
@@ -5,6 +5,7 @@
 //! Servo's media-query device and expression representation.
 
 use app_units::Au;
+use context::QuirksMode;
 use cssparser::Parser;
 use euclid::{Size2D, TypedSize2D};
 use font_metrics::ServoMetricsProvider;
@@ -128,12 +129,12 @@ impl Expression {
 
     /// Evaluate this expression and return whether it matches the current
     /// device.
-    pub fn matches(&self, device: &Device) -> bool {
+    pub fn matches(&self, device: &Device, quirks_mode: QuirksMode) -> bool {
         let viewport_size = device.au_viewport_size();
         let value = viewport_size.width;
         match self.0 {
             ExpressionKind::Width(ref range) => {
-                match range.to_computed_range(device) {
+                match range.to_computed_range(device, quirks_mode) {
                     Range::Min(ref width) => { value >= *width },
                     Range::Max(ref width) => { value <= *width },
                     Range::Eq(ref width) => { value == *width },
@@ -175,7 +176,7 @@ pub enum Range<T> {
 }
 
 impl Range<specified::Length> {
-    fn to_computed_range(&self, device: &Device) -> Range<Au> {
+    fn to_computed_range(&self, device: &Device, quirks_mode: QuirksMode) -> Range<Au> {
         let default_values = device.default_computed_values();
         // http://dev.w3.org/csswg/mediaqueries3/#units
         // em units are relative to the initial font-size.
@@ -192,6 +193,7 @@ impl Range<specified::Length> {
             // ch units can exist in media queries.
             font_metrics_provider: &ServoMetricsProvider,
             in_media_query: true,
+            quirks_mode: quirks_mode,
         };
 
         match *self {
diff --git a/components/style/stylesheets.rs b/components/style/stylesheets.rs
index 9986328cb00..97dfce4c51f 100644
--- a/components/style/stylesheets.rs
+++ b/components/style/stylesheets.rs
@@ -7,6 +7,7 @@
 #![deny(missing_docs)]
 
 use {Atom, Prefix, Namespace};
+use context::QuirksMode;
 use counter_style::{CounterStyleRule, parse_counter_style_name, parse_counter_style_body};
 use cssparser::{AtRuleParser, Parser, QualifiedRuleParser};
 use cssparser::{AtRuleType, RuleListParser, parse_one_rule};
@@ -263,6 +264,8 @@ pub struct Stylesheet {
     pub dirty_on_viewport_size_change: AtomicBool,
     /// Whether this stylesheet should be disabled.
     pub disabled: AtomicBool,
+    /// The quirks mode of this stylesheet.
+    pub quirks_mode: QuirksMode,
 }
 
 
@@ -415,7 +418,8 @@ impl CssRule {
                                          &parent_stylesheet.url_data,
                                          &error_reporter,
                                          None,
-                                         LengthParsingMode::Default);
+                                         LengthParsingMode::Default,
+                                         parent_stylesheet.quirks_mode);
         let mut input = Parser::new(css);
 
         // nested rules are in the body state
@@ -663,7 +667,7 @@ impl Stylesheet {
         let (rules, dirty_on_viewport_size_change) = Stylesheet::parse_rules(
             css, url_data, existing.origin, &mut namespaces,
             &existing.shared_lock, stylesheet_loader, error_reporter,
-            0u64);
+            existing.quirks_mode, 0u64);
 
         *existing.namespaces.write() = namespaces;
         existing.dirty_on_viewport_size_change
@@ -681,6 +685,7 @@ impl Stylesheet {
                    shared_lock: &SharedRwLock,
                    stylesheet_loader: Option<&StylesheetLoader>,
                    error_reporter: &ParseErrorReporter,
+                   quirks_mode: QuirksMode,
                    line_number_offset: u64)
                    -> (Vec<CssRule>, bool) {
         let mut rules = Vec::new();
@@ -691,7 +696,8 @@ impl Stylesheet {
             shared_lock: shared_lock,
             loader: stylesheet_loader,
             context: ParserContext::new_with_line_number_offset(origin, url_data, error_reporter,
-                                                                line_number_offset, LengthParsingMode::Default),
+                                                                line_number_offset, LengthParsingMode::Default,
+                                                                quirks_mode),
             state: Cell::new(State::Start),
         };
 
@@ -726,11 +732,13 @@ impl Stylesheet {
                     shared_lock: SharedRwLock,
                     stylesheet_loader: Option<&StylesheetLoader>,
                     error_reporter: &ParseErrorReporter,
-                    line_number_offset: u64) -> Stylesheet {
+                    quirks_mode: QuirksMode,
+                    line_number_offset: u64)
+                    -> Stylesheet {
         let mut namespaces = Namespaces::default();
         let (rules, dirty_on_viewport_size_change) = Stylesheet::parse_rules(
             css, &url_data, origin, &mut namespaces,
-            &shared_lock, stylesheet_loader, error_reporter, line_number_offset
+            &shared_lock, stylesheet_loader, error_reporter, quirks_mode, line_number_offset,
         );
         Stylesheet {
             origin: origin,
@@ -741,6 +749,7 @@ impl Stylesheet {
             shared_lock: shared_lock,
             dirty_on_viewport_size_change: AtomicBool::new(dirty_on_viewport_size_change),
             disabled: AtomicBool::new(false),
+            quirks_mode: quirks_mode,
         }
     }
 
@@ -769,7 +778,7 @@ impl Stylesheet {
     ///
     /// Always true if no associated MediaList exists.
     pub fn is_effective_for_device(&self, device: &Device, guard: &SharedRwLockReadGuard) -> bool {
-        self.media.read_with(guard).evaluate(device)
+        self.media.read_with(guard).evaluate(device, self.quirks_mode)
     }
 
     /// Return an iterator over the effective rules within the style-sheet, as
@@ -781,7 +790,7 @@ impl Stylesheet {
     #[inline]
     pub fn effective_rules<F>(&self, device: &Device, guard: &SharedRwLockReadGuard, mut f: F)
     where F: FnMut(&CssRule) {
-        effective_rules(&self.rules.read_with(guard).0, device, guard, &mut f);
+        effective_rules(&self.rules.read_with(guard).0, device, self.quirks_mode, guard, &mut f);
     }
 
     /// Returns whether the stylesheet has been explicitly disabled through the
@@ -802,17 +811,22 @@ impl Stylesheet {
     }
 }
 
-fn effective_rules<F>(rules: &[CssRule], device: &Device, guard: &SharedRwLockReadGuard, f: &mut F)
-where F: FnMut(&CssRule) {
+fn effective_rules<F>(rules: &[CssRule],
+                      device: &Device,
+                      quirks_mode: QuirksMode,
+                      guard: &SharedRwLockReadGuard,
+                      f: &mut F)
+    where F: FnMut(&CssRule)
+{
     for rule in rules {
         f(rule);
         rule.with_nested_rules_and_mq(guard, |rules, mq| {
             if let Some(media_queries) = mq {
-                if !media_queries.evaluate(device) {
+                if !media_queries.evaluate(device, quirks_mode) {
                     return
                 }
             }
-            effective_rules(rules, device, guard, f)
+            effective_rules(rules, device, quirks_mode, guard, f)
         })
     }
 }
@@ -973,6 +987,7 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                                 namespaces: RwLock::new(Namespaces::default()),
                                 dirty_on_viewport_size_change: AtomicBool::new(false),
                                 disabled: AtomicBool::new(false),
+                                quirks_mode: self.context.quirks_mode,
                             })
                         }
                     }, &mut |import_rule| {
diff --git a/components/style/stylist.rs b/components/style/stylist.rs
index 190226bb0cc..630fbd6d995 100644
--- a/components/style/stylist.rs
+++ b/components/style/stylist.rs
@@ -240,7 +240,7 @@ impl Stylist {
         };
 
         self.viewport_constraints =
-            ViewportConstraints::maybe_new(&self.device, &cascaded_rule);
+            ViewportConstraints::maybe_new(&self.device, &cascaded_rule, self.quirks_mode);
 
         if let Some(ref constraints) = self.viewport_constraints {
             Arc::get_mut(&mut self.device).unwrap()
@@ -418,7 +418,8 @@ impl Stylist {
                                 None,
                                 &RustLogReporter,
                                 font_metrics,
-                                cascade_flags);
+                                cascade_flags,
+                                self.quirks_mode);
         ComputedStyle::new(rule_node, Arc::new(computed))
     }
 
@@ -536,7 +537,8 @@ impl Stylist {
                                 None,
                                 &RustLogReporter,
                                 font_metrics,
-                                CascadeFlags::empty());
+                                CascadeFlags::empty(),
+                                self.quirks_mode);
 
         Some(ComputedStyle::new(rule_node, Arc::new(computed)))
     }
@@ -569,22 +571,22 @@ impl Stylist {
         };
 
         self.viewport_constraints =
-            ViewportConstraints::maybe_new(&device, &cascaded_rule);
+            ViewportConstraints::maybe_new(&device, &cascaded_rule, self.quirks_mode);
 
         if let Some(ref constraints) = self.viewport_constraints {
             device.account_for_viewport_rule(constraints);
         }
 
         fn mq_eval_changed(guard: &SharedRwLockReadGuard, rules: &[CssRule],
-                           before: &Device, after: &Device) -> bool {
+                           before: &Device, after: &Device, quirks_mode: QuirksMode) -> bool {
             for rule in rules {
                 let changed = rule.with_nested_rules_and_mq(guard, |rules, mq| {
                     if let Some(mq) = mq {
-                        if mq.evaluate(before) != mq.evaluate(after) {
+                        if mq.evaluate(before, quirks_mode) != mq.evaluate(after, quirks_mode) {
                             return true
                         }
                     }
-                    mq_eval_changed(guard, rules, before, after)
+                    mq_eval_changed(guard, rules, before, after, quirks_mode)
                 });
                 if changed {
                     return true
@@ -594,11 +596,11 @@ impl Stylist {
         }
         self.is_device_dirty |= stylesheets.iter().any(|stylesheet| {
             let mq = stylesheet.media.read_with(guard);
-            if mq.evaluate(&self.device) != mq.evaluate(&device) {
+            if mq.evaluate(&self.device, self.quirks_mode) != mq.evaluate(&device, self.quirks_mode) {
                 return true
             }
 
-            mq_eval_changed(guard, &stylesheet.rules.read_with(guard).0, &self.device, &device)
+            mq_eval_changed(guard, &stylesheet.rules.read_with(guard).0, &self.device, &device, self.quirks_mode)
         });
 
         self.device = Arc::new(device);
@@ -866,7 +868,8 @@ impl Stylist {
                                      None,
                                      &RustLogReporter,
                                      &metrics,
-                                     CascadeFlags::empty()))
+                                     CascadeFlags::empty(),
+                                     self.quirks_mode))
     }
 }
 
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 85a8ba19368..3e2ff2ceb89 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -4,6 +4,7 @@
 
 //! Computed values.
 
+use context::QuirksMode;
 use euclid::size::Size2D;
 use font_metrics::FontMetricsProvider;
 use media_queries::Device;
@@ -63,6 +64,9 @@ pub struct Context<'a> {
 
     /// Whether or not we are computing the media list in a media query
     pub in_media_query: bool,
+
+    /// The quirks mode of this context.
+    pub quirks_mode: QuirksMode,
 }
 
 impl<'a> Context<'a> {
diff --git a/components/style/viewport.rs b/components/style/viewport.rs
index 4c05ff52107..90811fa8549 100644
--- a/components/style/viewport.rs
+++ b/components/style/viewport.rs
@@ -10,6 +10,7 @@
 #![deny(missing_docs)]
 
 use app_units::Au;
+use context::QuirksMode;
 use cssparser::{AtRuleParser, DeclarationListParser, DeclarationParser, Parser, parse_important};
 use cssparser::ToCss as ParserToCss;
 use euclid::size::TypedSize2D;
@@ -588,13 +589,15 @@ pub trait MaybeNew {
     /// Create a ViewportConstraints from a viewport size and a `@viewport`
     /// rule.
     fn maybe_new(device: &Device,
-                 rule: &ViewportRule)
+                 rule: &ViewportRule,
+                 quirks_mode: QuirksMode)
                  -> Option<ViewportConstraints>;
 }
 
 impl MaybeNew for ViewportConstraints {
     fn maybe_new(device: &Device,
-                 rule: &ViewportRule)
+                 rule: &ViewportRule,
+                 quirks_mode: QuirksMode)
                  -> Option<ViewportConstraints>
     {
         use std::cmp;
@@ -684,6 +687,7 @@ impl MaybeNew for ViewportConstraints {
             style: device.default_computed_values().clone(),
             font_metrics_provider: &provider,
             in_media_query: false,
+            quirks_mode: quirks_mode,
         };
 
         // DEVICE-ADAPT § 9.3 Resolving 'extend-to-zoom'
diff --git a/ports/geckolib/glue.rs b/ports/geckolib/glue.rs
index 7e463db9d13..f9dadbfb7f1 100644
--- a/ports/geckolib/glue.rs
+++ b/ports/geckolib/glue.rs
@@ -511,7 +511,7 @@ pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyl
     Arc::new(Stylesheet::from_str(
         "", unsafe { dummy_url_data() }.clone(), origin,
         Arc::new(shared_lock.wrap(MediaList::empty())),
-        shared_lock, None, &RustLogReporter, 0u64)
+        shared_lock, None, &RustLogReporter, QuirksMode::NoQuirks, Wh0u64)
     ).into_strong()
 }
 
@@ -554,7 +554,7 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(loader: *mut Loader,
 
     Arc::new(Stylesheet::from_str(
         input, url_data.clone(), origin, media,
-        shared_lock, loader, &RustLogReporter, 0u64)
+        shared_lock, loader, &RustLogReporter, QuirksMode::NoQuirks, 0u64)
     ).into_strong()
 }
 
@@ -1007,7 +1007,8 @@ pub extern "C" fn Servo_ParseProperty(property: nsCSSPropertyID, value: *const n
     let url_data = unsafe { RefPtr::from_ptr_ref(&data) };
     let reporter = RustLogReporter;
     let context = ParserContext::new(Origin::Author, url_data, &reporter,
-                                     Some(CssRuleType::Style), LengthParsingMode::Default);
+                                     Some(CssRuleType::Style), LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
 
     match ParsedDeclaration::parse(id, &context, &mut Parser::new(value)) {
         Ok(parsed) => {
@@ -1030,7 +1031,8 @@ pub extern "C" fn Servo_ParseEasing(easing: *const nsAString,
     let url_data = unsafe { RefPtr::from_ptr_ref(&data) };
     let reporter = RustLogReporter;
     let context = ParserContext::new(Origin::Author, url_data, &reporter,
-                                     Some(CssRuleType::Style), LengthParsingMode::Default);
+                                     Some(CssRuleType::Style), LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
     let easing = unsafe { (*easing).to_string() };
     match transition_timing_function::single_value::parse(&context, &mut Parser::new(&easing)) {
         Ok(parsed_easing) => {
@@ -1171,7 +1173,7 @@ fn set_property(declarations: RawServoDeclarationBlockBorrowed, property_id: Pro
         structs::LengthParsingMode::SVG => LengthParsingMode::SVG,
     };
     if let Ok(parsed) = parse_one_declaration(property_id, value, url_data, &RustLogReporter,
-                                              length_parsing_mode) {
+                                              length_parsing_mode, QuirksMode::NoQuirks) {
         let importance = if is_important { Importance::Important } else { Importance::Normal };
         write_locked_arc(declarations, |decls: &mut PropertyDeclarationBlock| {
             parsed.expand_set_into(decls, importance)
@@ -1238,7 +1240,7 @@ pub extern "C" fn Servo_MediaList_Matches(list: RawServoMediaListBorrowed,
                                           -> bool {
     let per_doc_data = PerDocumentStyleData::from_ffi(raw_data).borrow();
     read_locked_arc(list, |list: &MediaList| {
-        list.evaluate(&per_doc_data.stylist.device)
+        list.evaluate(&per_doc_data.stylist.device, QuirksMode::NoQuirks)
     })
 }
 
@@ -1265,7 +1267,8 @@ pub extern "C" fn Servo_MediaList_SetText(list: RawServoMediaListBorrowed, text:
     let url_data = unsafe { dummy_url_data() };
     let reporter = RustLogReporter;
     let context = ParserContext::new_for_cssom(url_data, &reporter, Some(CssRuleType::Media),
-                                               LengthParsingMode::Default);
+                                               LengthParsingMode::Default,
+                                               QuirksMode::NoQuirks);
      write_locked_arc(list, |list: &mut MediaList| {
         *list = parse_media_query_list(&context, &mut parser);
     })
@@ -1296,7 +1299,8 @@ pub extern "C" fn Servo_MediaList_AppendMedium(list: RawServoMediaListBorrowed,
     let url_data = unsafe { dummy_url_data() };
     let reporter = RustLogReporter;
     let context = ParserContext::new_for_cssom(url_data, &reporter, Some(CssRuleType::Media),
-                                               LengthParsingMode::Default);
+                                               LengthParsingMode::Default,
+                                               QuirksMode::NoQuirks);
     write_locked_arc(list, |list: &mut MediaList| {
         list.append_medium(&context, new_medium);
     })
@@ -1309,7 +1313,8 @@ pub extern "C" fn Servo_MediaList_DeleteMedium(list: RawServoMediaListBorrowed,
     let url_data = unsafe { dummy_url_data() };
     let reporter = RustLogReporter;
     let context = ParserContext::new_for_cssom(url_data, &reporter, Some(CssRuleType::Media),
-                                               LengthParsingMode::Default);
+                                               LengthParsingMode::Default,
+                                               QuirksMode::NoQuirks);
     write_locked_arc(list, |list: &mut MediaList| list.delete_medium(&context, old_medium))
 }
 
@@ -1662,7 +1667,8 @@ pub extern "C" fn Servo_DeclarationBlock_SetBackgroundImage(declarations:
     let string = unsafe { (*value).to_string() };
     let error_reporter = RustLogReporter;
     let context = ParserContext::new(Origin::Author, url_data, &error_reporter,
-                                     Some(CssRuleType::Style), LengthParsingMode::Default);
+                                     Some(CssRuleType::Style), LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
     if let Ok(url) = SpecifiedUrl::parse_from_string(string.into(), &context) {
         let decl = PropertyDeclaration::BackgroundImage(BackgroundImage(
             vec![SingleBackgroundImage(
@@ -1700,7 +1706,12 @@ pub extern "C" fn Servo_CSSSupports2(property: *const nsACString, value: *const
     let value = unsafe { value.as_ref().unwrap().as_str_unchecked() };
 
     let url_data = unsafe { dummy_url_data() };
-    parse_one_declaration(id, &value, url_data, &RustLogReporter, LengthParsingMode::Default).is_ok()
+    parse_one_declaration(id,
+                          &value,
+                          url_data,
+                          &RustLogReporter,
+                          LengthParsingMode::Default,
+                          QuirksMode::NoQuirks).is_ok()
 }
 
 #[no_mangle]
@@ -1712,7 +1723,8 @@ pub extern "C" fn Servo_CSSSupports(cond: *const nsACString) -> bool {
         let url_data = unsafe { dummy_url_data() };
         let reporter = RustLogReporter;
         let context = ParserContext::new_for_cssom(url_data, &reporter, Some(CssRuleType::Style),
-                                                   LengthParsingMode::Default);
+                                                   LengthParsingMode::Default,
+                                                   QuirksMode::NoQuirks);
         cond.eval(&context)
     } else {
         false
@@ -1944,6 +1956,7 @@ pub extern "C" fn Servo_GetComputedKeyframeValues(keyframes: RawGeckoKeyframeLis
         style: (**style).clone(),
         font_metrics_provider: &metrics,
         in_media_query: false,
+        quirks_mode: QuirksMode::NoQuirks,
     };
 
     for (index, keyframe) in keyframes.iter().enumerate() {
diff --git a/tests/unit/style/media_queries.rs b/tests/unit/style/media_queries.rs
index f256d296c9f..10634a6f134 100644
--- a/tests/unit/style/media_queries.rs
+++ b/tests/unit/style/media_queries.rs
@@ -8,6 +8,7 @@ use servo_url::ServoUrl;
 use std::borrow::ToOwned;
 use std::sync::Arc;
 use style::Atom;
+use style::context::QuirksMode;
 use style::error_reporting::ParseErrorReporter;
 use style::media_queries::*;
 use style::servo::media_queries::*;
@@ -37,7 +38,7 @@ fn test_media_rule<F>(css: &str, callback: F)
     let media_list = Arc::new(lock.wrap(MediaList::empty()));
     let stylesheet = Stylesheet::from_str(
         css, url, Origin::Author, media_list, lock,
-        None, &CSSErrorReporterTest, 0u64);
+        None, &CSSErrorReporterTest, QuirksMode::NoQuirks, 0u64);
     let mut rule_count = 0;
     let guard = stylesheet.shared_lock.read();
     media_queries(&guard, &stylesheet.rules.read_with(&guard).0, &mut |mq| {
@@ -66,7 +67,7 @@ fn media_query_test(device: &Device, css: &str, expected_rule_count: usize) {
     let media_list = Arc::new(lock.wrap(MediaList::empty()));
     let ss = Stylesheet::from_str(
         css, url, Origin::Author, media_list, lock,
-        None, &CSSErrorReporterTest, 0u64);
+        None, &CSSErrorReporterTest, QuirksMode::NoQuirks, 0u64);
     let mut rule_count = 0;
     ss.effective_style_rules(device, &ss.shared_lock.read(), |_| rule_count += 1);
     assert!(rule_count == expected_rule_count, css.to_owned());
diff --git a/tests/unit/style/parsing/image.rs b/tests/unit/style/parsing/image.rs
index 78a6b04eed9..158f99aaa4e 100644
--- a/tests/unit/style/parsing/image.rs
+++ b/tests/unit/style/parsing/image.rs
@@ -5,6 +5,7 @@
 use euclid::size::TypedSize2D;
 use parsing::parse;
 use std::f32::consts::PI;
+use style::context::QuirksMode;
 use style::font_metrics::ServoMetricsProvider;
 use style::media_queries::{Device, MediaType};
 use style::properties::ComputedValues;
@@ -51,6 +52,7 @@ fn test_linear_gradient() {
         style: initial_style.clone(),
         font_metrics_provider: &ServoMetricsProvider,
         in_media_query: false,
+        quirks_mode: QuirksMode::NoQuirks,
     };
     assert_eq!(specified::AngleOrCorner::None.to_computed_value(&specified_context),
                computed::AngleOrCorner::Angle(Angle::from_radians(PI)));
diff --git a/tests/unit/style/parsing/length.rs b/tests/unit/style/parsing/length.rs
index ad0b77d2e01..b6d9a30b42c 100644
--- a/tests/unit/style/parsing/length.rs
+++ b/tests/unit/style/parsing/length.rs
@@ -5,6 +5,7 @@
 use cssparser::Parser;
 use media_queries::CSSErrorReporterTest;
 use parsing::parse;
+use style::context::QuirksMode;
 use style::parser::{LengthParsingMode, Parse, ParserContext};
 use style::stylesheets::{CssRuleType, Origin};
 use style::values::specified::length::{AbsoluteLength, Length, NoCalcLength};
@@ -38,7 +39,8 @@ fn test_length_parsing_modes() {
     let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
     let reporter = CSSErrorReporterTest;
     let context = ParserContext::new(Origin::Author, &url, &reporter,
-                                     Some(CssRuleType::Style), LengthParsingMode::SVG);
+                                     Some(CssRuleType::Style), LengthParsingMode::SVG,
+                                     QuirksMode::NoQuirks);
     let mut parser = Parser::new("1");
     let result = Length::parse(&context, &mut parser);
     assert!(result.is_ok());
diff --git a/tests/unit/style/parsing/mod.rs b/tests/unit/style/parsing/mod.rs
index 79efb4a3484..6ba2043bd95 100644
--- a/tests/unit/style/parsing/mod.rs
+++ b/tests/unit/style/parsing/mod.rs
@@ -6,6 +6,7 @@
 
 use cssparser::Parser;
 use media_queries::CSSErrorReporterTest;
+use style::context::QuirksMode;
 use style::parser::{LengthParsingMode, ParserContext};
 use style::stylesheets::{CssRuleType, Origin};
 
@@ -13,7 +14,8 @@ fn parse<T, F: Fn(&ParserContext, &mut Parser) -> Result<T, ()>>(f: F, s: &str)
     let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
     let reporter = CSSErrorReporterTest;
     let context = ParserContext::new(Origin::Author, &url, &reporter, Some(CssRuleType::Style),
-                                     LengthParsingMode::Default);
+                                     LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
     let mut parser = Parser::new(s);
     f(&context, &mut parser)
 }
diff --git a/tests/unit/style/properties/mod.rs b/tests/unit/style/properties/mod.rs
index 68aae4dacca..747b0bd6571 100644
--- a/tests/unit/style/properties/mod.rs
+++ b/tests/unit/style/properties/mod.rs
@@ -4,6 +4,7 @@
 
 use cssparser::Parser;
 use media_queries::CSSErrorReporterTest;
+use style::context::QuirksMode;
 use style::parser::{LengthParsingMode, ParserContext};
 use style::stylesheets::{CssRuleType, Origin};
 
@@ -11,7 +12,8 @@ fn parse<T, F: Fn(&ParserContext, &mut Parser) -> Result<T, ()>>(f: F, s: &str)
     let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
     let reporter = CSSErrorReporterTest;
     let context = ParserContext::new(Origin::Author, &url, &reporter, Some(CssRuleType::Style),
-                                     LengthParsingMode::Default);
+                                     LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
     let mut parser = Parser::new(s);
     f(&context, &mut parser)
 }
diff --git a/tests/unit/style/rule_tree/bench.rs b/tests/unit/style/rule_tree/bench.rs
index 96b63cfe2fb..ed73bd11d6f 100644
--- a/tests/unit/style/rule_tree/bench.rs
+++ b/tests/unit/style/rule_tree/bench.rs
@@ -6,6 +6,7 @@ use cssparser::{Parser, SourcePosition};
 use rayon;
 use servo_url::ServoUrl;
 use std::sync::Arc;
+use style::context::QuirksMode;
 use style::error_reporting::ParseErrorReporter;
 use style::media_queries::MediaList;
 use style::properties::{longhands, Importance, PropertyDeclaration, PropertyDeclarationBlock};
@@ -58,6 +59,7 @@ fn parse_rules(css: &str) -> Vec<(StyleSource, CascadeLevel)> {
                                  lock,
                                  None,
                                  &ErrorringErrorReporter,
+                                 QuirksMode::NoQuirks,
                                  0u64);
     let guard = s.shared_lock.read();
     let rules = s.rules.read_with(&guard);
diff --git a/tests/unit/style/stylesheets.rs b/tests/unit/style/stylesheets.rs
index dd1762ee686..47aa1ea9730 100644
--- a/tests/unit/style/stylesheets.rs
+++ b/tests/unit/style/stylesheets.rs
@@ -13,6 +13,7 @@ use std::borrow::ToOwned;
 use std::sync::Arc;
 use std::sync::Mutex;
 use std::sync::atomic::AtomicBool;
+use style::context::QuirksMode;
 use style::error_reporting::ParseErrorReporter;
 use style::keyframes::{Keyframe, KeyframeSelector, KeyframePercentage};
 use style::media_queries::MediaList;
@@ -66,7 +67,7 @@ fn test_parse_stylesheet() {
     let lock = SharedRwLock::new();
     let media = Arc::new(lock.wrap(MediaList::empty()));
     let stylesheet = Stylesheet::from_str(css, url.clone(), Origin::UserAgent, media, lock,
-                                          None, &CSSErrorReporterTest, 0u64);
+                                          None, &CSSErrorReporterTest, QuirksMode::NoQuirks, 0u64);
     let mut namespaces = Namespaces::default();
     namespaces.default = Some(ns!(html));
     let expected = Stylesheet {
@@ -77,6 +78,7 @@ fn test_parse_stylesheet() {
         url_data: url,
         dirty_on_viewport_size_change: AtomicBool::new(false),
         disabled: AtomicBool::new(false),
+        quirks_mode: QuirksMode::NoQuirks,
         rules: CssRules::new(vec![
             CssRule::Namespace(Arc::new(stylesheet.shared_lock.wrap(NamespaceRule {
                 prefix: None,
@@ -316,7 +318,7 @@ fn test_report_error_stylesheet() {
     let lock = SharedRwLock::new();
     let media = Arc::new(lock.wrap(MediaList::empty()));
     Stylesheet::from_str(css, url.clone(), Origin::UserAgent, media, lock,
-                         None, &error_reporter, 5u64);
+                         None, &error_reporter, QuirksMode::NoQuirks, 5u64);
 
     let mut errors = errors.lock().unwrap();
 
diff --git a/tests/unit/style/viewport.rs b/tests/unit/style/viewport.rs
index 150546ee588..fb29e87debf 100644
--- a/tests/unit/style/viewport.rs
+++ b/tests/unit/style/viewport.rs
@@ -8,6 +8,7 @@ use media_queries::CSSErrorReporterTest;
 use servo_config::prefs::{PREFS, PrefValue};
 use servo_url::ServoUrl;
 use std::sync::Arc;
+use style::context::QuirksMode;
 use style::media_queries::{Device, MediaList, MediaType};
 use style::parser::{LengthParsingMode, Parse, ParserContext};
 use style::shared_lock::SharedRwLock;
@@ -32,6 +33,7 @@ macro_rules! stylesheet {
             $shared_lock,
             None,
             &$error_reporter,
+            QuirksMode::NoQuirks,
             0u64
         ))
     }
@@ -293,7 +295,8 @@ fn constrain_viewport() {
     let url = ServoUrl::parse("http://localhost").unwrap();
     let reporter = CSSErrorReporterTest;
     let context = ParserContext::new(Origin::Author, &url, &reporter, Some(CssRuleType::Viewport),
-                                     LengthParsingMode::Default);
+                                     LengthParsingMode::Default,
+                                     QuirksMode::NoQuirks);
 
     macro_rules! from_css {
         ($css:expr) => {
@@ -303,9 +306,9 @@ fn constrain_viewport() {
 
     let initial_viewport = TypedSize2D::new(800., 600.);
     let device = Device::new(MediaType::Screen, initial_viewport);
-    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("")), None);
+    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!(""), QuirksMode::NoQuirks), None);
 
-    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto")),
+    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto"), QuirksMode::NoQuirks),
                Some(ViewportConstraints {
                    size: initial_viewport,
 
@@ -317,7 +320,7 @@ fn constrain_viewport() {
                    orientation: Orientation::Auto
                }));
 
-    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto")),
+    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto"), QuirksMode::NoQuirks),
                Some(ViewportConstraints {
                    size: initial_viewport,
 
@@ -329,10 +332,12 @@ fn constrain_viewport() {
                    orientation: Orientation::Auto
                }));
 
-    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 800px; height: 600px;\
-                                                                     zoom: 1;\
-                                                                     user-zoom: zoom;\
-                                                                     orientation: auto;")),
+    assert_eq!(ViewportConstraints::maybe_new(&device,
+                                              from_css!("width: 800px; height: 600px;\
+                                                         zoom: 1;\
+                                                         user-zoom: zoom;\
+                                                         orientation: auto;"),
+                                              QuirksMode::NoQuirks),
                Some(ViewportConstraints {
                    size: initial_viewport,
 
@@ -346,7 +351,7 @@ fn constrain_viewport() {
 
     let initial_viewport = TypedSize2D::new(200., 150.);
     let device = Device::new(MediaType::Screen, initial_viewport);
-    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto")),
+    assert_eq!(ViewportConstraints::maybe_new(&device, from_css!("width: 320px auto"), QuirksMode::NoQuirks),
                Some(ViewportConstraints {
                    size: TypedSize2D::new(320., 240.),