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>

layout/style/MediaList.h

@@ -69,6 +69,10 @@ public:
   virtual bool Matches(nsPresContext& aPresContext,
                        nsMediaQueryResultCacheKey* = nullptr) const = 0;
 
+#ifdef DEBUG
+  virtual bool IsServo() const = 0;
+#endif
+
   void SetStyleSheet(StyleSheet* aSheet);
 
   NS_DECL_NSIDOMMEDIALIST

layout/style/ServoBindingList.h

@@ -29,6 +29,7 @@ SERVO_BINDING_FUNC(Servo_StyleSheet_FromUTF8Bytes, RawServoStyleSheetStrong,
                    mozilla::ServoStyleSheet* gecko_stylesheet,
                    const nsACString* data,
                    mozilla::css::SheetParsingMode parsing_mode,
+                   const RawServoMediaList* media_list,
                    RawGeckoURLExtraData* extra_data)
 SERVO_BINDING_FUNC(Servo_ImportRule_GetSheet,
                    RawServoStyleSheetStrong,

layout/style/ServoMediaList.h

@@ -33,6 +33,12 @@ public:
 
   bool Matches(nsPresContext&, nsMediaQueryResultCacheKey*) const final;
 
+#ifdef DEBUG
+  bool IsServo() const final { return true; }
+#endif
+
+  RawServoMediaList& RawList() { return *mRawList; }
+
 protected:
   nsresult Delete(const nsAString& aOldMedium) final;
   nsresult Append(const nsAString& aNewMedium) final;

layout/style/ServoStyleSheet.cpp

@@ -9,9 +9,11 @@
 #include "mozilla/css/Rule.h"
 #include "mozilla/StyleBackendType.h"
 #include "mozilla/ServoBindings.h"
+#include "mozilla/ServoMediaList.h"
 #include "mozilla/ServoCSSRuleList.h"
 #include "mozilla/css/GroupRule.h"
 #include "mozilla/dom/CSSRuleList.h"
+#include "mozilla/dom/MediaList.h"
 
 #include "mozAutoDocUpdate.h"
 
@@ -97,15 +99,22 @@ ServoStyleSheet::ParseSheet(css::Loader* aLoader,
                             nsIPrincipal* aSheetPrincipal,
                             uint32_t aLineNumber)
 {
+  MOZ_ASSERT_IF(mMedia, mMedia->IsServo());
   RefPtr<URLExtraData> extraData =
     new URLExtraData(aBaseURI, aSheetURI, aSheetPrincipal);
 
   NS_ConvertUTF16toUTF8 input(aInput);
   if (!Inner()->mSheet) {
+    auto* mediaList = static_cast<ServoMediaList*>(mMedia.get());
+    RawServoMediaList* media = mediaList ?  &mediaList->RawList() : nullptr;
+
     Inner()->mSheet =
-      Servo_StyleSheet_FromUTF8Bytes(aLoader, this, &input,
-                                     mParsingMode, extraData).Consume();
+      Servo_StyleSheet_FromUTF8Bytes(
+          aLoader, this, &input, mParsingMode, media, extraData).Consume();
   } else {
+    // TODO(emilio): Once we have proper inner cloning (which we don't right
+    // now) we should update the mediaList here too, though it's slightly
+    // tricky.
     Servo_StyleSheet_ClearAndUpdate(Inner()->mSheet, aLoader,
                                     this, &input, extraData);
   }

layout/style/nsMediaList.h

@@ -260,6 +260,10 @@ public:
   bool Matches(nsPresContext& aPresContext,
                nsMediaQueryResultCacheKey* aKey) const final;
 
+#ifdef DEBUG
+  bool IsServo() const final { return false; }
+#endif
+
   void AppendQuery(nsAutoPtr<nsMediaQuery>& aQuery) {
     // Takes ownership of aQuery
     mArray.AppendElement(aQuery.forget());

layout/style/test/gtest/StyloParsingBench.cpp

@@ -28,7 +28,7 @@ static void ServoParsingBench() {
     NullPrincipalURI::Create(), nullptr, NullPrincipal::Create());
   for (int i = 0; i < PARSING_REPETITIONS; i++) {
     RefPtr<RawServoStyleSheet> stylesheet = Servo_StyleSheet_FromUTF8Bytes(
-      nullptr, nullptr, &css, eAuthorSheetFeatures, data
+      nullptr, nullptr, &css, eAuthorSheetFeatures, nullptr, data
     ).Consume();
   }
 }