Bug 1415940 Part 3: Make StyleSheets clear their MODIFIED_RULES flag when the sheet is reparsed. r=bz

MozReview-Commit-ID: F7g2CstgjT8

--HG--
extra : rebase_source : 6bd59483739a24edebc00ce62eaef554c63d4842

layout/style/CSSStyleSheet.cpp

@@ -930,6 +930,10 @@ CSSStyleSheet::ReparseSheet(const nsAString& aInput)
     }
     RuleAdded(*rule);
   }
+
+  // Our rules are no longer considered modified.
+  ClearModifiedRules();
+
   return NS_OK;
 }
 

layout/style/ServoStyleSheet.cpp

@@ -328,6 +328,9 @@ ServoStyleSheet::ReparseSheet(const nsAString& aInput)
     }
   }
 
+  // Our rules are no longer considered modified.
+  ClearModifiedRules();
+
   return NS_OK;
 }
 

layout/style/StyleSheet.h

@@ -136,6 +136,7 @@ public:
                                              FORCED_UNIQUE_INNER; }
   bool HasModifiedRules() const { return mDirtyFlags &
                                          MODIFIED_RULES; }
+  void ClearModifiedRules() { mDirtyFlags &= ~MODIFIED_RULES; }
 
   inline bool HasUniqueInner() const;
   void EnsureUniqueInner();