Auto merge of #16378 - emilio:media-fixes, r=upsuper

stylo: A bunch of media query fixes.

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components/layout_thread/lib.rs

@@ -113,7 +113,7 @@ use style::data::StoredRestyleHint;
 use style::dom::{ShowSubtree, ShowSubtreeDataAndPrimaryValues, TElement, TNode};
 use style::error_reporting::StdoutErrorReporter;
 use style::logical_geometry::LogicalPoint;
-use style::media_queries::{Device, MediaType};
+use style::media_queries::{Device, MediaList, MediaType};
 use style::servo::restyle_damage::{REFLOW, REFLOW_OUT_OF_FLOW, REPAINT, REPOSITION, STORE_OVERFLOW};
 use style::shared_lock::{SharedRwLock, SharedRwLockReadGuard, StylesheetGuards};
 use style::stylesheets::{Origin, Stylesheet, UserAgentStylesheets};
@@ -1583,7 +1583,7 @@ fn get_ua_stylesheets() -> Result<UserAgentStylesheets, &'static str> {
             None,
             None,
             Origin::UserAgent,
-            Default::default(),
+            MediaList::empty(),
             shared_lock.clone(),
             None,
             &StdoutErrorReporter))
@@ -1598,7 +1598,7 @@ 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, Default::default(),
+            &contents, url.clone(), None, None, Origin::User, MediaList::empty(),
             shared_lock.clone(), None, &StdoutErrorReporter));
     }
 

components/script/dom/cssrulelist.rs

@@ -15,7 +15,7 @@ use dom::window::Window;
 use dom_struct::dom_struct;
 use std::sync::Arc;
 use style::shared_lock::Locked;
-use style::stylesheets::{CssRules, KeyframesRule, RulesMutateError};
+use style::stylesheets::{CssRules, CssRulesHelpers, KeyframesRule, RulesMutateError};
 
 #[allow(unsafe_code)]
 unsafe_no_jsmanaged_fields!(RulesSource);
@@ -90,15 +90,13 @@ impl CSSRuleList {
         let index = idx as usize;
 
         let parent_stylesheet = self.parent_stylesheet.style_stylesheet();
-        let new_rule = {
-            let mut guard = parent_stylesheet.shared_lock.write();
-            // FIXME We should probably pass in a proper StylesheetLoader.
-            //       See servo/servo#16240
-            css_rules.write_with(&mut guard).insert_rule(rule, parent_stylesheet,
-                                                         index, nested, None)?
-            // Drop `guard` here,
-            // CSSRule::new_specific re-acquires the lock for @support and @media.
-        };
+        let new_rule =
+            css_rules.insert_rule(&parent_stylesheet.shared_lock,
+                                  rule,
+                                  parent_stylesheet,
+                                  index,
+                                  nested,
+                                  None)?;
 
         let parent_stylesheet = &*self.parent_stylesheet;
         let dom_rule = CSSRule::new_specific(&window, parent_stylesheet, new_rule);

components/script/dom/htmlmetaelement.rs

@@ -24,6 +24,7 @@ use std::ascii::AsciiExt;
 use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use style::attr::AttrValue;
+use style::media_queries::MediaList;
 use style::str::HTML_SPACE_CHARACTERS;
 use style::stylesheets::{Stylesheet, CssRule, CssRules, Origin};
 use style::viewport::ViewportRule;
@@ -107,7 +108,7 @@ impl HTMLMetaElement {
                         shared_lock: shared_lock.clone(),
                         url_data: window_from_node(self).get_url(),
                         namespaces: Default::default(),
-                        media: Arc::new(shared_lock.wrap(Default::default())),
+                        media: Arc::new(shared_lock.wrap(MediaList::empty())),
                         // Viewport constraints are always recomputed on resize; they don't need to
                         // force all styles to be recomputed.
                         dirty_on_viewport_size_change: AtomicBool::new(false),

components/script/dom/htmlstyleelement.rs

@@ -86,8 +86,9 @@ impl HTMLStyleElement {
         let context = CssParserContext::new_for_cssom(&url,
                                                       win.css_error_reporter(),
                                                       Some(CssRuleType::Media));
-        let mq = parse_media_query_list(&context, &mut CssParser::new(&mq_str));
         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))));
         let loader = StylesheetLoader::for_element(self.upcast());
         let sheet = Stylesheet::from_str(&data, win.get_url(), Origin::Author, mq,
                                          shared_lock, Some(&loader),

components/script/dom/medialist.rs

@@ -67,7 +67,7 @@ impl MediaListMethods for MediaList {
         // Step 2
         if value.is_empty() {
             // Step 1
-            *media_queries = StyleMediaList::default();
+            *media_queries = StyleMediaList::empty();
             return;
         }
         // Step 3

components/script/stylesheet_loader.rs

@@ -271,15 +271,15 @@ impl<'a> StylesheetLoader<'a> {
 impl<'a> StyleStylesheetLoader for StylesheetLoader<'a> {
     fn request_stylesheet(
         &self,
-        media: MediaList,
-        make_import: &mut FnMut(MediaList) -> ImportRule,
+        media: Arc<StyleLocked<MediaList>>,
+        make_import: &mut FnMut(Arc<StyleLocked<MediaList>>) -> ImportRule,
         make_arc: &mut FnMut(ImportRule) -> Arc<StyleLocked<ImportRule>>,
     ) -> Arc<StyleLocked<ImportRule>> {
         let import = make_import(media);
         let url = import.url.url().expect("Invalid urls shouldn't enter the loader").clone();
 
-        //TODO (mrnayak) : Whether we should use the original loader's CORS setting?
-        //Fix this when spec has more details.
+        // TODO (mrnayak) : Whether we should use the original loader's CORS
+        // setting? Fix this when spec has more details.
         let source = StylesheetContextSource::Import(import.stylesheet.clone());
         self.load(source, url, None, "".to_owned());
 

components/style/encoding_support.rs

@@ -12,6 +12,7 @@ use media_queries::MediaList;
 use self::encoding::{EncodingRef, DecoderTrap};
 use shared_lock::SharedRwLock;
 use std::str;
+use std::sync::Arc;
 use stylesheets::{Stylesheet, StylesheetLoader, Origin, UrlExtraData};
 
 struct RustEncoding;
@@ -62,7 +63,7 @@ impl Stylesheet {
         Stylesheet::from_str(&string,
                              url_data,
                              origin,
-                             media,
+                             Arc::new(shared_lock.wrap(media)),
                              shared_lock,
                              stylesheet_loader,
                              error_reporter)

components/style/gecko_bindings/bindings.rs

@@ -463,7 +463,7 @@ extern "C" {
                                 child_sheet: RawServoStyleSheetBorrowed,
                                 base_url_data: *mut RawGeckoURLExtraData,
                                 url_bytes: *const u8, url_length: u32,
-                                media_bytes: *const u8, media_length: u32);
+                                media_list: RawServoMediaListStrong);
 }
 extern "C" {
     pub fn Gecko_MaybeCreateStyleChildrenIterator(node: RawGeckoNodeBorrowed)
@@ -1461,6 +1461,8 @@ extern "C" {
                                               *mut ServoStyleSheet,
                                           data: *const nsACString,
                                           parsing_mode: SheetParsingMode,
+                                          media_list:
+                                              *const RawServoMediaList,
                                           extra_data:
                                               *mut RawGeckoURLExtraData)
      -> RawServoStyleSheetStrong;
@@ -1914,6 +1916,17 @@ extern "C" {
     pub fn Servo_DeclarationBlock_SetTextDecorationColorOverride(declarations:
                                                                      RawServoDeclarationBlockBorrowed);
 }
+extern "C" {
+    pub fn Servo_MediaList_Create() -> RawServoMediaListStrong;
+}
+extern "C" {
+    pub fn Servo_MediaList_DeepClone(list: RawServoMediaListBorrowed)
+     -> RawServoMediaListStrong;
+}
+extern "C" {
+    pub fn Servo_MediaList_Matches(list: RawServoMediaListBorrowed,
+                                   set: RawServoStyleSetBorrowed) -> bool;
+}
 extern "C" {
     pub fn Servo_MediaList_GetText(list: RawServoMediaListBorrowed,
                                    result: *mut nsAString);

components/style/media_queries.rs

@@ -20,7 +20,7 @@ pub use servo::media_queries::{Device, Expression};
 pub use gecko::media_queries::{Device, Expression};
 
 /// A type that encapsulates a media query list.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct MediaList {
     /// The list of media queries.
@@ -35,8 +35,9 @@ impl ToCss for MediaList {
     }
 }
 
-impl Default for MediaList {
-    fn default() -> MediaList {
+impl MediaList {
+    /// Create an empty MediaList.
+    pub fn empty() -> Self {
         MediaList { media_queries: vec![] }
     }
 }
@@ -251,7 +252,7 @@ impl MediaQuery {
 /// https://drafts.csswg.org/mediaqueries/#error-handling
 pub fn parse_media_query_list(context: &ParserContext, input: &mut Parser) -> MediaList {
     if input.is_exhausted() {
-        return Default::default()
+        return MediaList::empty()
     }
 
     let mut media_queries = vec![];

components/style/stylesheets.rs

@@ -135,53 +135,6 @@ impl CssRules {
         })
     }
 
-    /// https://drafts.csswg.org/cssom/#insert-a-css-rule
-    pub fn insert_rule(&mut self,
-                       rule: &str,
-                       parent_stylesheet: &Stylesheet,
-                       index: usize,
-                       nested: bool,
-                       loader: Option<&StylesheetLoader>)
-                       -> Result<CssRule, RulesMutateError> {
-        // Step 1, 2
-        if index > self.0.len() {
-            return Err(RulesMutateError::IndexSize);
-        }
-
-        // Computes the parser state at the given index
-        let state = if nested {
-            None
-        } else if index == 0 {
-            Some(State::Start)
-        } else {
-            self.0.get(index - 1).map(CssRule::rule_state)
-        };
-
-        // Step 3, 4
-        // XXXManishearth should we also store the namespace map?
-        let (new_rule, new_state) =
-            try!(CssRule::parse(&rule, parent_stylesheet, state, loader));
-
-        // Step 5
-        // Computes the maximum allowed parser state at a given index.
-        let rev_state = self.0.get(index).map_or(State::Body, CssRule::rule_state);
-        if new_state > rev_state {
-            // We inserted a rule too early, e.g. inserting
-            // a regular style rule before @namespace rules
-            return Err(RulesMutateError::HierarchyRequest);
-        }
-
-        // Step 6
-        if let CssRule::Namespace(..) = new_rule {
-            if !self.only_ns_or_import() {
-                return Err(RulesMutateError::InvalidState);
-            }
-        }
-
-        self.0.insert(index, new_rule.clone());
-        Ok(new_rule)
-    }
-
     /// https://drafts.csswg.org/cssom/#remove-a-css-rule
     pub fn remove_rule(&mut self, index: usize) -> Result<(), RulesMutateError> {
         // Step 1, 2
@@ -207,6 +160,86 @@ impl CssRules {
     }
 }
 
+/// A trait to implement helpers for `Arc<Locked<CssRules>>`.
+pub trait CssRulesHelpers {
+    /// https://drafts.csswg.org/cssom/#insert-a-css-rule
+    ///
+    /// Written in this funky way because parsing an @import rule may cause us
+    /// to clone a stylesheet from the same document due to caching in the CSS
+    /// loader.
+    ///
+    /// TODO(emilio): We could also pass the write guard down into the loader
+    /// instead, but that seems overkill.
+    fn insert_rule(&self,
+                   lock: &SharedRwLock,
+                   rule: &str,
+                   parent_stylesheet: &Stylesheet,
+                   index: usize,
+                   nested: bool,
+                   loader: Option<&StylesheetLoader>)
+                   -> Result<CssRule, RulesMutateError>;
+}
+
+impl CssRulesHelpers for Arc<Locked<CssRules>> {
+    fn insert_rule(&self,
+                   lock: &SharedRwLock,
+                   rule: &str,
+                   parent_stylesheet: &Stylesheet,
+                   index: usize,
+                   nested: bool,
+                   loader: Option<&StylesheetLoader>)
+                   -> Result<CssRule, RulesMutateError> {
+        let state = {
+            let read_guard = lock.read();
+            let rules = self.read_with(&read_guard);
+
+            // Step 1, 2
+            if index > rules.0.len() {
+                return Err(RulesMutateError::IndexSize);
+            }
+
+            // Computes the parser state at the given index
+            if nested {
+                None
+            } else if index == 0 {
+                Some(State::Start)
+            } else {
+                rules.0.get(index - 1).map(CssRule::rule_state)
+            }
+        };
+
+        // Step 3, 4
+        // XXXManishearth should we also store the namespace map?
+        let (new_rule, new_state) =
+            try!(CssRule::parse(&rule, parent_stylesheet, state, loader));
+
+        {
+            let mut write_guard = lock.write();
+            let mut rules = self.write_with(&mut write_guard);
+            // Step 5
+            // Computes the maximum allowed parser state at a given index.
+            let rev_state = rules.0.get(index).map_or(State::Body, CssRule::rule_state);
+            if new_state > rev_state {
+                // We inserted a rule too early, e.g. inserting
+                // a regular style rule before @namespace rules
+                return Err(RulesMutateError::HierarchyRequest);
+            }
+
+            // Step 6
+            if let CssRule::Namespace(..) = new_rule {
+                if !rules.only_ns_or_import() {
+                    return Err(RulesMutateError::InvalidState);
+                }
+            }
+
+            rules.0.insert(index, new_rule.clone());
+        }
+
+        Ok(new_rule)
+    }
+
+}
+
 /// The structure servo uses to represent a stylesheet.
 #[derive(Debug)]
 pub struct Stylesheet {
@@ -690,7 +723,7 @@ impl Stylesheet {
     pub fn from_str(css: &str,
                     url_data: UrlExtraData,
                     origin: Origin,
-                    media: MediaList,
+                    media: Arc<Locked<MediaList>>,
                     shared_lock: SharedRwLock,
                     stylesheet_loader: Option<&StylesheetLoader>,
                     error_reporter: &ParseErrorReporter) -> Stylesheet {
@@ -704,7 +737,7 @@ impl Stylesheet {
             url_data: url_data,
             namespaces: RwLock::new(namespaces),
             rules: CssRules::new(rules, &shared_lock),
-            media: Arc::new(shared_lock.wrap(media)),
+            media: media,
             shared_lock: shared_lock,
             dirty_on_viewport_size_change: AtomicBool::new(dirty_on_viewport_size_change),
             disabled: AtomicBool::new(false),
@@ -825,8 +858,8 @@ pub trait StylesheetLoader {
     /// before they’re locked, while keeping the trait object-safe.
     fn request_stylesheet(
         &self,
-        media: MediaList,
-        make_import: &mut FnMut(MediaList) -> ImportRule,
+        media: Arc<Locked<MediaList>>,
+        make_import: &mut FnMut(Arc<Locked<MediaList>>) -> ImportRule,
         make_arc: &mut FnMut(ImportRule) -> Arc<Locked<ImportRule>>,
     ) -> Arc<Locked<ImportRule>>;
 }
@@ -836,8 +869,8 @@ struct NoOpLoader;
 impl StylesheetLoader for NoOpLoader {
     fn request_stylesheet(
         &self,
-        media: MediaList,
-        make_import: &mut FnMut(MediaList) -> ImportRule,
+        media: Arc<Locked<MediaList>>,
+        make_import: &mut FnMut(Arc<Locked<MediaList>>) -> ImportRule,
         make_arc: &mut FnMut(ImportRule) -> Arc<Locked<ImportRule>>,
     ) -> Arc<Locked<ImportRule>> {
         make_arc(make_import(media))
@@ -906,6 +939,7 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                     let specified_url = SpecifiedUrl::parse_from_string(url_string, &self.context)?;
 
                     let media = parse_media_query_list(&self.context, input);
+                    let media = Arc::new(self.shared_lock.wrap(media));
 
                     let noop_loader = NoOpLoader;
                     let loader = if !specified_url.is_invalid() {
@@ -920,7 +954,7 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                             url: specified_url.take().unwrap(),
                             stylesheet: Arc::new(Stylesheet {
                                 rules: CssRules::new(Vec::new(), self.shared_lock),
-                                media: Arc::new(self.shared_lock.wrap(media)),
+                                media: media,
                                 shared_lock: self.shared_lock.clone(),
                                 origin: self.context.stylesheet_origin,
                                 url_data: self.context.url_data.clone(),

ports/geckolib/glue.rs

@@ -30,7 +30,7 @@ use style::gecko::wrapper::GeckoElement;
 use style::gecko_bindings::bindings;
 use style::gecko_bindings::bindings::{RawGeckoKeyframeListBorrowed, RawGeckoKeyframeListBorrowedMut};
 use style::gecko_bindings::bindings::{RawServoDeclarationBlockBorrowed, RawServoDeclarationBlockStrong};
-use style::gecko_bindings::bindings::{RawServoMediaListBorrowed, RawServoMediaListStrong};
+use style::gecko_bindings::bindings::{RawServoMediaList, RawServoMediaListBorrowed, RawServoMediaListStrong};
 use style::gecko_bindings::bindings::{RawServoMediaRule, RawServoMediaRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoNamespaceRule, RawServoNamespaceRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoPageRule, RawServoPageRuleBorrowed};
@@ -83,8 +83,9 @@ use style::selector_parser::PseudoElementCascadeType;
 use style::sequential;
 use style::shared_lock::{SharedRwLock, SharedRwLockReadGuard, StylesheetGuards, ToCssWithGuard, Locked};
 use style::string_cache::Atom;
-use style::stylesheets::{CssRule, CssRules, CssRuleType, ImportRule, MediaRule, NamespaceRule, PageRule};
-use style::stylesheets::{Origin, Stylesheet, StyleRule};
+use style::stylesheets::{CssRule, CssRules, CssRuleType, CssRulesHelpers};
+use style::stylesheets::{ImportRule, MediaRule, NamespaceRule, Origin};
+use style::stylesheets::{PageRule, Stylesheet, StyleRule};
 use style::stylesheets::StylesheetLoader as StyleStylesheetLoader;
 use style::supports::parse_condition_or_declaration;
 use style::thread_state;
@@ -494,7 +495,8 @@ pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyl
     let shared_lock = global_style_data.shared_lock.clone();
     Arc::new(Stylesheet::from_str(
         "", unsafe { dummy_url_data() }.clone(), origin,
-        Default::default(), shared_lock, None, &StdoutErrorReporter)
+        Arc::new(shared_lock.wrap(MediaList::empty())),
+        shared_lock, None, &StdoutErrorReporter)
     ).into_strong()
 }
 
@@ -503,6 +505,7 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(loader: *mut Loader,
                                                  stylesheet: *mut ServoStyleSheet,
                                                  data: *const nsACString,
                                                  mode: SheetParsingMode,
+                                                 media_list: *const RawServoMediaList,
                                                  extra_data: *mut URLExtraData)
                                                  -> RawServoStyleSheetStrong {
     let global_style_data = &*GLOBAL_STYLE_DATA;
@@ -528,8 +531,14 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(loader: *mut Loader,
     };
 
     let shared_lock = global_style_data.shared_lock.clone();
+    let media = if media_list.is_null() {
+        Arc::new(shared_lock.wrap(MediaList::empty()))
+    } else {
+        Locked::<MediaList>::as_arc(unsafe { &&*media_list }).clone()
+    };
+
     Arc::new(Stylesheet::from_str(
-        input, url_data.clone(), origin, Default::default(),
+        input, url_data.clone(), origin, media,
         shared_lock, loader, &StdoutErrorReporter)
     ).into_strong()
 }
@@ -698,15 +707,20 @@ pub extern "C" fn Servo_CssRules_InsertRule(rules: ServoCssRulesBorrowed,
     };
     let loader = loader.as_ref().map(|loader| loader as &StyleStylesheetLoader);
     let rule = unsafe { rule.as_ref().unwrap().as_str_unchecked() };
-    write_locked_arc(rules, |rules: &mut CssRules| {
-        match rules.insert_rule(rule, sheet, index as usize, nested, loader) {
-            Ok(new_rule) => {
-                *unsafe { rule_type.as_mut().unwrap() } = new_rule.rule_type() as u16;
-                nsresult::NS_OK
-            }
-            Err(err) => err.into()
+
+    let global_style_data = &*GLOBAL_STYLE_DATA;
+    match Locked::<CssRules>::as_arc(&rules).insert_rule(&global_style_data.shared_lock,
+                                                         rule,
+                                                         sheet,
+                                                         index as usize,
+                                                         nested,
+                                                         loader) {
+        Ok(new_rule) => {
+            *unsafe { rule_type.as_mut().unwrap() } = new_rule.rule_type() as u16;
+            nsresult::NS_OK
         }
-    })
+        Err(err) => err.into(),
+    }
 }
 
 #[no_mangle]
@@ -1192,6 +1206,31 @@ pub extern "C" fn Servo_DeclarationBlock_RemovePropertyById(declarations: RawSer
     remove_property(declarations, get_property_id_from_nscsspropertyid!(property, ()))
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_MediaList_Create() -> RawServoMediaListStrong {
+    let global_style_data = &*GLOBAL_STYLE_DATA;
+    Arc::new(global_style_data.shared_lock.wrap(MediaList::empty())).into_strong()
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_MediaList_DeepClone(list: RawServoMediaListBorrowed) -> RawServoMediaListStrong {
+    let global_style_data = &*GLOBAL_STYLE_DATA;
+    read_locked_arc(list, |list: &MediaList| {
+        Arc::new(global_style_data.shared_lock.wrap(list.clone()))
+            .into_strong()
+    })
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_MediaList_Matches(list: RawServoMediaListBorrowed,
+                                          raw_data: RawServoStyleSetBorrowed)
+                                          -> bool {
+    let per_doc_data = PerDocumentStyleData::from_ffi(raw_data).borrow();
+    read_locked_arc(list, |list: &MediaList| {
+        list.evaluate(&per_doc_data.stylist.device)
+    })
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_MediaList_GetText(list: RawServoMediaListBorrowed, result: *mut nsAString) {
     read_locked_arc(list, |list: &MediaList| {

ports/geckolib/stylesheet_loader.rs

@@ -5,11 +5,10 @@
 use std::sync::Arc;
 use style::gecko_bindings::bindings::Gecko_LoadStyleSheet;
 use style::gecko_bindings::structs::{Loader, ServoStyleSheet};
-use style::gecko_bindings::sugar::ownership::HasArcFFI;
+use style::gecko_bindings::sugar::ownership::{HasArcFFI, FFIArcHelpers};
 use style::media_queries::MediaList;
 use style::shared_lock::Locked;
 use style::stylesheets::{ImportRule, Stylesheet, StylesheetLoader as StyleStylesheetLoader};
-use style_traits::ToCss;
 
 pub struct StylesheetLoader(*mut Loader, *mut ServoStyleSheet);
 
@@ -22,21 +21,11 @@ impl StylesheetLoader {
 impl StyleStylesheetLoader for StylesheetLoader {
     fn request_stylesheet(
         &self,
-        media: MediaList,
-        make_import: &mut FnMut(MediaList) -> ImportRule,
+        media: Arc<Locked<MediaList>>,
+        make_import: &mut FnMut(Arc<Locked<MediaList>>) -> ImportRule,
         make_arc: &mut FnMut(ImportRule) -> Arc<Locked<ImportRule>>,
     ) -> Arc<Locked<ImportRule>> {
-        // TODO(emilio): We probably want to share media representation with
-        // Gecko in Stylo.
-        //
-        // This also allows us to get rid of a bunch of extra work to evaluate
-        // and ensure parity, and shouldn't be much Gecko work given we always
-        // evaluate them on the main thread.
-        //
-        // Meanwhile, this works.
-        let media_string = media.to_css_string();
-
-        let import = make_import(media);
+        let import = make_import(media.clone());
 
         // After we get this raw pointer ImportRule will be moved into a lock and Arc
         // and so the Arc<Url> pointer inside will also move,
@@ -52,8 +41,7 @@ impl StyleStylesheetLoader for StylesheetLoader {
                                  base_url_data,
                                  spec_bytes,
                                  spec_len as u32,
-                                 media_string.as_bytes().as_ptr(),
-                                 media_string.len() as u32);
+                                 media.into_strong())
         }
         make_arc(import)
     }

tests/unit/style/media_queries.rs

@@ -6,6 +6,7 @@ use cssparser::{Parser, SourcePosition};
 use euclid::size::TypedSize2D;
 use servo_url::ServoUrl;
 use std::borrow::ToOwned;
+use std::sync::Arc;
 use style::Atom;
 use style::error_reporting::ParseErrorReporter;
 use style::media_queries::*;
@@ -28,8 +29,10 @@ fn test_media_rule<F>(css: &str, callback: F)
 {
     let url = ServoUrl::parse("http://localhost").unwrap();
     let css_str = css.to_owned();
+    let lock = SharedRwLock::new();
+    let media_list = Arc::new(lock.wrap(MediaList::empty()));
     let stylesheet = Stylesheet::from_str(
-        css, url, Origin::Author, Default::default(), SharedRwLock::new(),
+        css, url, Origin::Author, media_list, lock,
         None, &CSSErrorReporterTest);
     let mut rule_count = 0;
     let guard = stylesheet.shared_lock.read();
@@ -55,8 +58,10 @@ fn media_queries<F>(guard: &SharedRwLockReadGuard, rules: &[CssRule], f: &mut F)
 
 fn media_query_test(device: &Device, css: &str, expected_rule_count: usize) {
     let url = ServoUrl::parse("http://localhost").unwrap();
+    let lock = SharedRwLock::new();
+    let media_list = Arc::new(lock.wrap(MediaList::empty()));
     let ss = Stylesheet::from_str(
-        css, url, Origin::Author, Default::default(), SharedRwLock::new(),
+        css, url, Origin::Author, media_list, lock,
         None, &CSSErrorReporterTest);
     let mut rule_count = 0;
     ss.effective_style_rules(device, &ss.shared_lock.read(), |_| rule_count += 1);

tests/unit/style/rule_tree/bench.rs

@@ -42,13 +42,14 @@ impl<'a> Drop for AutoGCRuleTree<'a> {
 }
 
 fn parse_rules(css: &str) -> Vec<(StyleSource, CascadeLevel)> {
+    let lock = SharedRwLock::new();
+    let media = Arc::new(lock.wrap(MediaList::empty()));
+
     let s = Stylesheet::from_str(css,
                                  ServoUrl::parse("http://localhost").unwrap(),
                                  Origin::Author,
-                                 MediaList {
-                                     media_queries: vec![],
-                                 },
-                                 SharedRwLock::new(),
+                                 media,
+                                 lock,
                                  None,
                                  &ErrorringErrorReporter);
     let guard = s.shared_lock.read();

tests/unit/style/stylesheets.rs

@@ -15,6 +15,7 @@ use std::sync::Mutex;
 use std::sync::atomic::AtomicBool;
 use style::error_reporting::ParseErrorReporter;
 use style::keyframes::{Keyframe, KeyframeSelector, KeyframePercentage};
+use style::media_queries::MediaList;
 use style::properties::Importance;
 use style::properties::{CSSWideKeyword, DeclaredValueOwned, PropertyDeclaration, PropertyDeclarationBlock};
 use style::properties::longhands;
@@ -61,14 +62,15 @@ fn test_parse_stylesheet() {
             }
         }";
     let url = ServoUrl::parse("about::test").unwrap();
-    let stylesheet = Stylesheet::from_str(css, url.clone(), Origin::UserAgent, Default::default(),
-                                          SharedRwLock::new(), None,
-                                          &CSSErrorReporterTest);
+    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);
     let mut namespaces = Namespaces::default();
     namespaces.default = Some(ns!(html));
     let expected = Stylesheet {
         origin: Origin::UserAgent,
-        media: Arc::new(stylesheet.shared_lock.wrap(Default::default())),
+        media: Arc::new(stylesheet.shared_lock.wrap(MediaList::empty())),
         shared_lock: stylesheet.shared_lock.clone(),
         namespaces: RwLock::new(namespaces),
         url_data: url,
@@ -323,9 +325,10 @@ fn test_report_error_stylesheet() {
 
     let errors = error_reporter.errors.clone();
 
-    Stylesheet::from_str(css, url.clone(), Origin::UserAgent, Default::default(),
-                         SharedRwLock::new(), None,
-                         &error_reporter);
+    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);
 
     let mut errors = errors.lock().unwrap();
 

tests/unit/style/viewport.rs

@@ -7,7 +7,8 @@ use euclid::size::TypedSize2D;
 use media_queries::CSSErrorReporterTest;
 use servo_config::prefs::{PREFS, PrefValue};
 use servo_url::ServoUrl;
-use style::media_queries::{Device, MediaType};
+use std::sync::Arc;
+use style::media_queries::{Device, MediaList, MediaType};
 use style::parser::{Parse, ParserContext};
 use style::shared_lock::SharedRwLock;
 use style::stylesheets::{CssRuleType, Stylesheet, Origin};
@@ -27,7 +28,7 @@ macro_rules! stylesheet {
             $css,
             ServoUrl::parse("http://localhost").unwrap(),
             Origin::$origin,
-            Default::default(),
+            Arc::new($shared_lock.wrap(MediaList::empty())),
             $shared_lock,
             None,
             &$error_reporter