Bug 1026033, part 2 - Make StyleRule::mImportantRule into an nsRefPtr. r=bz

layout/style/StyleRule.cpp

@@ -1307,7 +1307,6 @@ StyleRule::StyleRule(nsCSSSelectorList* aSelector,
   : Rule(),
     mSelector(aSelector),
     mDeclaration(aDeclaration),
-    mImportantRule(nullptr),
     mLineNumber(0),
     mColumnNumber(0),
     mWasMatched(false)
@@ -1320,7 +1319,6 @@ StyleRule::StyleRule(const StyleRule& aCopy)
   : Rule(aCopy),
     mSelector(aCopy.mSelector ? aCopy.mSelector->Clone() : nullptr),
     mDeclaration(new Declaration(*aCopy.mDeclaration)),
-    mImportantRule(nullptr),
     mLineNumber(aCopy.mLineNumber),
     mColumnNumber(aCopy.mColumnNumber),
     mWasMatched(false)
@@ -1334,7 +1332,6 @@ StyleRule::StyleRule(StyleRule& aCopy,
   : Rule(aCopy),
     mSelector(aCopy.mSelector),
     mDeclaration(aDeclaration),
-    mImportantRule(nullptr),
     mDOMRule(aCopy.mDOMRule.forget()),
     mLineNumber(aCopy.mLineNumber),
     mColumnNumber(aCopy.mColumnNumber),
@@ -1360,7 +1357,6 @@ StyleRule::~StyleRule()
 {
   delete mSelector;
   delete mDeclaration;
-  NS_IF_RELEASE(mImportantRule);
   if (mDOMRule) {
     mDOMRule->DOMDeclaration()->DropReference();
   }
@@ -1390,7 +1386,7 @@ StyleRule::RuleMatched()
     mWasMatched = true;
     mDeclaration->SetImmutable();
     if (mDeclaration->HasImportantData()) {
-      NS_ADDREF(mImportantRule = new ImportantRule(mDeclaration));
+      mImportantRule = new ImportantRule(mDeclaration);
     }
   }
 }

layout/style/StyleRule.h

@@ -374,7 +374,7 @@ private:
 private:
   nsCSSSelectorList*      mSelector; // null for style attribute
   Declaration*            mDeclaration;
-  ImportantRule*          mImportantRule; // initialized by RuleMatched
+  nsRefPtr<ImportantRule> mImportantRule; // initialized by RuleMatched
   nsRefPtr<DOMCSSStyleRule> mDOMRule;
   // Keep the same type so that MSVC packs them.
   uint32_t                mLineNumber;