Bug 1325878: Pass the MediaList down to Servo, making <style media> work. r=xidorn

MozReview-Commit-ID: BUCSQJs2CNI
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>

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/media_queries.rs

@@ -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

@@ -723,7 +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 {
@@ -737,7 +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),