Bug 1290209 - Part 6: Move CSSStyleSheet::mMedia up to StyleSheet. r=bzbarsky

MozReview-Commit-ID: LZraHzme6vj

layout/style/CSSStyleSheet.cpp

@@ -418,12 +418,6 @@ CSSStyleSheet::CSSStyleSheet(const CSSStyleSheet& aCopy,
     // FIXME: handle failure?
     EnsureUniqueInner();
   }
-
-  if (aCopy.mMedia) {
-    // XXX This is wrong; we should be keeping @import rules and
-    // sheets in sync!
-    mMedia = aCopy.mMedia->Clone();
-  }
 }
 
 CSSStyleSheet::~CSSStyleSheet()
@@ -439,7 +433,6 @@ CSSStyleSheet::~CSSStyleSheet()
     }
   }
   DropRuleCollection();
-  DropMedia();
   mInner->RemoveSheet(this);
   // XXX The document reference is not reference counted and should
   // not be released. The document will let us know when it is going
@@ -462,15 +455,6 @@ CSSStyleSheet::DropRuleCollection()
   }
 }
 
-void
-CSSStyleSheet::DropMedia()
-{
-  if (mMedia) {
-    mMedia->SetStyleSheet(nullptr);
-    mMedia = nullptr;
-  }
-}
-
 void
 CSSStyleSheet::UnlinkInner()
 {
@@ -543,7 +527,6 @@ NS_IMPL_RELEASE_INHERITED(CSSStyleSheet, StyleSheet)
 NS_IMPL_CYCLE_COLLECTION_CLASS(CSSStyleSheet)
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CSSStyleSheet)
-  tmp->DropMedia();
   // We do not unlink mNext; our parent will handle that.  If we
   // unlinked it here, our parent would not be able to walk its list
   // of child sheets and null out the back-references to it, if we got
@@ -553,7 +536,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CSSStyleSheet)
   tmp->mScopeElement = nullptr;
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(StyleSheet)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(CSSStyleSheet, StyleSheet)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMedia)
   // We do not traverse mNext; our parent will handle that.  See
   // comments in Unlink for why.
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRuleCollection)
@@ -611,12 +593,6 @@ CSSStyleSheet::UseForPresentation(nsPresContext* aPresContext,
 }
 
 
-void
-CSSStyleSheet::SetMedia(nsMediaList* aMedia)
-{
-  mMedia = aMedia;
-}
-
 bool
 CSSStyleSheet::HasRules() const
 {
@@ -909,17 +885,6 @@ CSSStyleSheet::RegisterNamespaceRule(css::Rule* aRule)
   return NS_OK;
 }
 
-nsMediaList*
-CSSStyleSheet::Media()
-{
-  if (!mMedia) {
-    mMedia = new nsMediaList();
-    mMedia->SetStyleSheet(this);
-  }
-
-  return mMedia;
-}
-
 nsIDOMCSSRule*
 CSSStyleSheet::GetDOMOwnerRule() const
 {

layout/style/CSSStyleSheet.h

@@ -31,7 +31,6 @@
 class CSSRuleListImpl;
 class nsCSSRuleProcessor;
 class nsIURI;
-class nsMediaList;
 class nsMediaQueryResultCacheKey;
 class nsStyleSet;
 class nsPresContext;
@@ -148,8 +147,6 @@ public:
   nsresult DeleteRuleFromGroup(css::GroupRule* aGroup, uint32_t aIndex);
   nsresult InsertRuleIntoGroup(const nsAString& aRule, css::GroupRule* aGroup, uint32_t aIndex, uint32_t* _retval);
 
-  void SetMedia(nsMediaList* aMedia);
-
   void SetOwnerRule(css::ImportRule* aOwnerRule) { mOwnerRule = aOwnerRule; /* Not ref counted */ }
   css::ImportRule* GetOwnerRule() const { return mOwnerRule; }
   // Workaround overloaded-virtual warning in GCC.
@@ -204,9 +201,6 @@ public:
     mScopeElement = aScopeElement;
   }
 
-  // WebIDL StyleSheet API
-  nsMediaList* Media() final;
-
   // WebIDL CSSStyleSheet API
   // Can't be inline because we can't include ImportRule here.  And can't be
   // called GetOwnerRule because that would be ambiguous with the ImportRule
@@ -237,9 +231,6 @@ protected:
   // Drop our reference to mRuleCollection
   void DropRuleCollection();
 
-  // Drop our reference to mMedia
-  void DropMedia();
-
   // Unlink our inner, if needed, for cycle collection
   void UnlinkInner();
   // Traverse our inner, if needed, for cycle collection
@@ -252,7 +243,6 @@ protected:
                               uint32_t aIndex, ErrorResult& aRv);
   void DeleteRuleInternal(uint32_t aIndex, ErrorResult& aRv);
 
-  RefPtr<nsMediaList> mMedia;
   RefPtr<CSSStyleSheet> mNext;
   CSSStyleSheet*        mParent;    // weak ref
   css::ImportRule*      mOwnerRule; // weak ref

layout/style/Loader.cpp

@@ -1304,7 +1304,7 @@ Loader::PrepareSheet(StyleSheet* aSheet,
     mediumParser.ParseMediaList(aMediaString, nullptr, 0, mediaList);
   }
 
-  sheet->SetMedia(mediaList);
+  aSheet->SetMedia(mediaList);
 
   aSheet->SetTitle(aTitle);
   sheet->SetEnabled(!isAlternate);

layout/style/ServoStyleSheet.cpp

@@ -122,12 +122,6 @@ ServoStyleSheet::List(FILE* aOut, int32_t aIndex) const
 }
 #endif
 
-nsMediaList*
-ServoStyleSheet::Media()
-{
-  return nullptr;
-}
-
 nsIDOMCSSRule*
 ServoStyleSheet::GetDOMOwnerRule() const
 {

layout/style/ServoStyleSheet.h

@@ -66,9 +66,6 @@ public:
     mSheet = aSheet;
   }
 
-  // WebIDL StyleSheet API
-  nsMediaList* Media() final;
-
   // WebIDL CSSStyleSheet API
   // Can't be inline because we can't include ImportRule here.  And can't be
   // called GetOwnerRule because that would be ambiguous with the ImportRule

layout/style/StyleSheet.cpp

@@ -37,6 +37,16 @@ StyleSheet::StyleSheet(const StyleSheet& aCopy,
   , mType(aCopy.mType)
   , mDisabled(aCopy.mDisabled)
 {
+  if (aCopy.mMedia) {
+    // XXX This is wrong; we should be keeping @import rules and
+    // sheets in sync!
+    mMedia = aCopy.mMedia->Clone();
+  }
+}
+
+StyleSheet::~StyleSheet()
+{
+  DropMedia();
 }
 
 // QueryInterface implementation for StyleSheet
@@ -49,7 +59,18 @@ NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(StyleSheet)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(StyleSheet)
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(StyleSheet)
+NS_IMPL_CYCLE_COLLECTION_CLASS(StyleSheet)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(StyleSheet)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMedia)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(StyleSheet)
+  tmp->DropMedia();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(StyleSheet)
 
 mozilla::dom::CSSStyleSheetParsingMode
 StyleSheet::ParsingModeDOM()
@@ -320,6 +341,32 @@ StyleSheet::AreRulesAvailable(nsIPrincipal& aSubjectPrincipal,
   return true;
 }
 
+void
+StyleSheet::SetMedia(nsMediaList* aMedia)
+{
+  mMedia = aMedia;
+}
+
+void
+StyleSheet::DropMedia()
+{
+  if (mMedia) {
+    mMedia->SetStyleSheet(nullptr);
+    mMedia = nullptr;
+  }
+}
+
+nsMediaList*
+StyleSheet::Media()
+{
+  if (!mMedia) {
+    mMedia = new nsMediaList();
+    mMedia->SetStyleSheet(this);
+  }
+
+  return mMedia;
+}
+
 // nsWrapperCache
 
 JSObject*

layout/style/StyleSheet.h

@@ -44,7 +44,7 @@ protected:
   StyleSheet(const StyleSheet& aCopy,
              nsIDocument* aDocumentToUse,
              nsINode* aOwningNodeToUse);
-  virtual ~StyleSheet() {}
+  virtual ~StyleSheet();
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
@@ -112,6 +112,7 @@ public:
   inline void SetPrincipal(nsIPrincipal* aPrincipal);
 
   void SetTitle(const nsAString& aTitle) { mTitle = aTitle; }
+  void SetMedia(nsMediaList* aMedia);
 
   // Get this style sheet's CORS mode
   inline CORSMode GetCORSMode() const;
@@ -131,7 +132,7 @@ public:
   // GetOwnerNode is defined above.
   inline StyleSheet* GetParentStyleSheet() const;
   // The XPCOM GetTitle is fine for WebIDL.
-  virtual nsMediaList* Media() = 0;
+  nsMediaList* Media();
   bool Disabled() const { return mDisabled; }
   // The XPCOM SetDisabled is fine for WebIDL.
 
@@ -194,10 +195,15 @@ protected:
   void SubjectSubsumesInnerPrincipal(nsIPrincipal& aSubjectPrincipal,
                                      ErrorResult& aRv);
 
+  // Drop our reference to mMedia
+  void DropMedia();
+
   nsString              mTitle;
   nsIDocument*          mDocument; // weak ref; parents maintain this for their children
   nsINode*              mOwningNode; // weak ref
 
+  RefPtr<nsMediaList> mMedia;
+
   // mParsingMode controls access to nonstandard style constructs that
   // are not safe for use on the public Web but necessary in UA sheets
   // and/or useful in user sheets.