Bug 1339629 Part 8: Uplift ClearRuleCascades into StyleSheet. r=heycam

MozReview-Commit-ID: CCYIYjWrw86

--HG--
extra : rebase_source : c9f3e4bced29d46ab9c906e58e97465e60fda5ae

layout/style/CSSStyleSheet.cpp

@@ -573,9 +573,6 @@ CSSStyleSheet::EnsureUniqueInner()
 {
   StyleSheet::EnsureUniqueInner();
 
-  // otherwise the rule processor has pointers to the old rules
-  ClearRuleCascades();
-
   // let our containing style sets know that if we call
   // nsPresContext::EnsureSafeToHandOutCSSRules we will need to restyle the
   // document
@@ -628,9 +625,9 @@ CSSStyleSheet::List(FILE* out, int32_t aIndent) const
 #endif
 
 void 
-CSSStyleSheet::ClearRuleCascades()
+CSSStyleSheet::ClearRuleCascadesInternal()
 {
-  // We might be in ClearRuleCascades because we had a modification
+  // We might be in ClearRuleCascadesInternal because we had a modification
   // to the sheet that resulted in an nsCSSSelector being destroyed.
   // Tell the RestyleManager for each document we're used in
   // so that they can drop any nsCSSSelector pointers (used for
@@ -654,10 +651,6 @@ CSSStyleSheet::ClearRuleCascades()
       (*iter)->ClearRuleCascades();
     }
   }
-  if (mParent) {
-    CSSStyleSheet* parent = (CSSStyleSheet*)mParent;
-    parent->ClearRuleCascades();
-  }
 }
 
 void

layout/style/CSSStyleSheet.h

@@ -183,7 +183,7 @@ private:
 protected:
   virtual ~CSSStyleSheet();
 
-  void ClearRuleCascades();
+  void ClearRuleCascadesInternal() override;
 
   // Add the namespace mapping from this @namespace rule to our namespace map
   nsresult RegisterNamespaceRule(css::Rule* aRule);

layout/style/ServoStyleSet.h

@@ -280,6 +280,17 @@ public:
    */
   void NoteStyleSheetsChanged();
 
+  /**
+   * Helper for correctly calling RebuildStylist without paying the cost of an
+   * extra function call in the common no-rebuild-needed case.
+   */
+  void UpdateStylistIfNeeded()
+  {
+    if (StylistNeedsUpdate()) {
+      UpdateStylist();
+    }
+  }
+
 #ifdef DEBUG
   void AssertTreeIsClean();
 #else
@@ -469,17 +480,6 @@ private:
    */
   void UpdateStylist();
 
-  /**
-   * Helper for correctly calling RebuildStylist without paying the cost of an
-   * extra function call in the common no-rebuild-needed case.
-   */
-  void UpdateStylistIfNeeded()
-  {
-    if (StylistNeedsUpdate()) {
-      UpdateStylist();
-    }
-  }
-
   already_AddRefed<ServoComputedValues>
     ResolveStyleLazily(dom::Element* aElement, CSSPseudoElementType aPseudoType);
 

layout/style/ServoStyleSheet.cpp

@@ -213,6 +213,15 @@ ServoStyleSheet::Clone(StyleSheet* aCloneParent,
   return clone.forget();
 }
 
+void
+ServoStyleSheet::ClearRuleCascadesInternal()
+{
+  for (StyleSetHandle& setHandle : mStyleSets) {
+    setHandle->AsServo()->NoteStyleSheetsChanged();
+    setHandle->AsServo()->UpdateStylistIfNeeded();
+  }
+}
+
 CSSRuleList*
 ServoStyleSheet::GetCssRulesInternal(ErrorResult& aRv)
 {

layout/style/ServoStyleSheet.h

@@ -113,6 +113,8 @@ public:
 protected:
   virtual ~ServoStyleSheet();
 
+  void ClearRuleCascadesInternal() override;
+
   ServoStyleSheetInner* Inner() const
   {
     return static_cast<ServoStyleSheetInner*>(mInner);

layout/style/StyleSheet.cpp

@@ -127,6 +127,15 @@ StyleSheet::TraverseInner(nsCycleCollectionTraversalCallback &cb)
   }
 }
 
+void
+StyleSheet::ClearRuleCascades()
+{
+  ClearRuleCascadesInternal();
+  if (mParent) {
+    mParent->ClearRuleCascades();
+  }
+}
+
 // QueryInterface implementation for StyleSheet
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(StyleSheet)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
@@ -437,6 +446,9 @@ StyleSheet::EnsureUniqueInner()
   MOZ_ASSERT(clone);
   mInner->RemoveSheet(this);
   mInner = clone;
+
+  // Ensure we're using the new rules.
+  ClearRuleCascades();
 }
 
 // WebIDL CSSStyleSheet API

layout/style/StyleSheet.h

@@ -271,6 +271,9 @@ protected:
   // Traverse our inner, if needed, for cycle collection
   virtual void TraverseInner(nsCycleCollectionTraversalCallback &);
 
+  void ClearRuleCascades();
+  virtual void ClearRuleCascadesInternal() {}
+
   StyleSheet*           mParent;    // weak ref
 
   nsString              mTitle;