Bug 1384114: Move mRefCnt, Destroy() and HasSingleReference() to GeckoStyleContext. r=bholley

MozReview-Commit-ID: 5XzFYcohl3m

--HG--
extra : rebase_source : e26c5c93fe66d5023ff3a7924cd8538cfcba8727

layout/style/GeckoStyleContext.cpp

@@ -38,6 +38,7 @@ GeckoStyleContext::GeckoStyleContext(GeckoStyleContext* aParent,
                                      bool aSkipParentDisplayBasedStyleFixup)
   : nsStyleContext(aParent, aPseudoTag, aPseudoType)
   , mCachedResetData(nullptr)
+  , mRefCnt(0)
   , mChild(nullptr)
   , mEmptyChild(nullptr)
   , mRuleNode(Move(aRuleNode))
@@ -81,6 +82,21 @@ GeckoStyleContext::operator new(size_t sz, nsPresContext* aPresContext)
     AllocateByObjectID(eArenaObjectID_GeckoStyleContext, sz);
 }
 
+// Overridden to prevent the global delete from being called, since the memory
+// came out of an nsIArena instead of the global delete operator's heap.
+void
+GeckoStyleContext::Destroy()
+{
+  // Get the pres context.
+  RefPtr<nsPresContext> presContext = PresContext();
+  // Call our destructor.
+  this->~GeckoStyleContext();
+  // Don't let the memory be freed, since it will be recycled
+  // instead. Don't call the global operator delete.
+  presContext->PresShell()->
+    FreeByObjectID(eArenaObjectID_GeckoStyleContext, this);
+}
+
 GeckoStyleContext::~GeckoStyleContext()
 {
   nsPresContext *presContext = PresContext();

layout/style/GeckoStyleContext.h

@@ -138,6 +138,13 @@ public:
     return mRuleNode;
   }
 
+  bool HasSingleReference() const {
+    NS_ASSERTION(mRefCnt != 0,
+                 "do not call HasSingleReference on a newly created "
+                 "nsStyleContext with no references yet");
+    return mRefCnt == 1;
+  }
+
   void AddRef() {
     if (mRefCnt == UINT32_MAX) {
       NS_WARNING("refcount overflow, leaking object");
@@ -220,6 +227,8 @@ public:
   nsResetStyleData*       mCachedResetData; // Cached reset style data.
   nsInheritedStyleData    mCachedInheritedData; // Cached inherited style data
 
+  uint32_t mRefCnt;
+
 #ifdef DEBUG
   void AssertStructsNotUsedElsewhere(GeckoStyleContext* aDestroyingContext,
                                      int32_t aLevels) const;
@@ -228,6 +237,7 @@ public:
 private:
   // Helper for ClearCachedInheritedStyleDataOnDescendants.
   void DoClearCachedInheritedStyleDataOnDescendants(uint32_t aStructs);
+  void Destroy();
 
   // Children are kept in two circularly-linked lists.  The list anchor
   // is not part of the list (null for empty), and we point to the first

layout/style/nsStyleContext.cpp

@@ -84,7 +84,6 @@ nsStyleContext::nsStyleContext(nsStyleContext* aParent,
   : mParent(aParent)
   , mPseudoTag(aPseudoTag)
   , mBits(((uint64_t)aPseudoType) << NS_STYLE_CONTEXT_TYPE_SHIFT)
-  , mRefCnt(0)
 #ifdef DEBUG
   , mFrameRefCnt(0)
 #endif
@@ -435,7 +434,8 @@ void nsStyleContext::List(FILE* out, int32_t aIndent, bool aListDescendants)
     str.AppendLiteral("  ");
   }
   str.Append(nsPrintfCString("%p(%d) parent=%p ",
-                             (void*)this, mRefCnt, (void *)mParent));
+                             (void*)this, IsGecko() ? AsGecko()->mRefCnt : 0,
+                             (void *)mParent));
   if (mPseudoTag) {
     nsAutoString  buffer;
     mPseudoTag->ToString(buffer);
@@ -472,25 +472,6 @@ void nsStyleContext::List(FILE* out, int32_t aIndent, bool aListDescendants)
 }
 #endif
 
-// Overridden to prevent the global delete from being called, since the memory
-// came out of an nsIArena instead of the global delete operator's heap.
-void
-nsStyleContext::Destroy()
-{
-  if (IsGecko()) {
-    // Get the pres context.
-    RefPtr<nsPresContext> presContext = PresContext();
-    // Call our destructor.
-    this->AsGecko()->~GeckoStyleContext();
-    // Don't let the memory be freed, since it will be recycled
-    // instead. Don't call the global operator delete.
-    presContext->PresShell()->
-      FreeByObjectID(eArenaObjectID_GeckoStyleContext, this);
-  } else {
-    delete static_cast<ServoStyleContext*>(this);
-  }
-}
-
 already_AddRefed<GeckoStyleContext>
 NS_NewStyleContext(GeckoStyleContext* aParentContext,
                    nsIAtom* aPseudoTag,

layout/style/nsStyleContext.h

@@ -62,8 +62,6 @@ public:
 #endif
   MOZ_DECL_STYLO_CONVERT_METHODS(mozilla::GeckoStyleContext, mozilla::ServoStyleContext);
 
-  void Destroy();
-
   // These two methods are for use by ArenaRefPtr.
   static mozilla::ArenaObjectID ArenaObjectID()
   {
@@ -91,13 +89,6 @@ public:
   }
 #endif
 
-  bool HasSingleReference() const {
-    NS_ASSERTION(mRefCnt != 0,
-                 "do not call HasSingleReference on a newly created "
-                 "nsStyleContext with no references yet");
-    return mRefCnt == 1;
-  }
-
   inline nsPresContext* PresContext() const;
 
   inline mozilla::GeckoStyleContext* GetParent() const;
@@ -360,8 +351,6 @@ protected:
   //    nsStyleStruct.h.
   uint64_t                mBits;
 
-  uint32_t                mRefCnt;
-
 #ifdef DEBUG
   uint32_t                mFrameRefCnt; // number of frames that use this
                                         // as their style context