Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/TreeScope.h

 /*
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  * Copyright (C) 2012 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 84 matching lines @@
 
     bool applyAuthorStyles() const;
 
     // Used by the basic DOM mutation methods (e.g., appendChild()).
     void adoptIfNeeded(Node&);
 
     Node& rootNode() const { return m_rootNode; }
 
     IdTargetObserverRegistry& idTargetObserverRegistry() const { return *m_idTargetObserverRegistry.get(); }
 
+
+#if !ENABLE(OILPAN)
     // Nodes belonging to this scope hold guard references -
     // these are enough to keep the scope from being destroyed, but
     // not enough to keep it from removing its children. This allows a
     // node that outlives its scope to still have a valid document
     // pointer without introducing reference cycles.
     void guardRef()
     {
 #if ENABLE(OILPAN)

[tkent, 2014/04/24 01:20:24]

Here is in !ENABLE(OILPAN)

[Mads Ager (chromium), 2014/04/24 10:57:36]

Yeah, sorry, I thought I cleaned that up but most have lost the changes along
the way. Done now. The keep-alive persistent and all code related to it has been
removed. Also, the integer used for the guard ref count is removed in the oilpan
build.

         if (!m_guardRefCount) {
             ASSERT(!m_keepAlive);
             m_keepAlive = adoptPtr(new Persistent<TreeScope>(this));
         }
 #else
         ASSERT(!deletionHasBegun());
 #endif
         ++m_guardRefCount;
     }
 
     void guardDeref()
     {
         ASSERT(m_guardRefCount > 0);
 #if !ENABLE(OILPAN)

[tkent, 2014/04/24 01:20:24]

This is redundant because here is in !ENABLE(OILPAN)

[Mads Ager (chromium), 2014/04/24 10:57:36]

Done.

         ASSERT(!deletionHasBegun());
 #endif
         --m_guardRefCount;
 #if ENABLE(OILPAN)

[tkent, 2014/04/24 01:20:24]

Here is in !ENABLE(OILPAN).

[Mads Ager (chromium), 2014/04/24 10:57:36]

Done.

         if (!m_guardRefCount)
             clearKeepAlive();
 #else
         if (!m_guardRefCount && !refCount() && !rootNodeHasTreeSharedParent()) {
             beginDeletion();
             delete this;
         }
 #endif
     }
+#endif
 
     void removedLastRefToScope();
 
 #if ENABLE(OILPAN)
     void clearKeepAlive()
     {
         ASSERT(m_keepAlive);
         m_keepAlive = nullptr;
     }
 #endif
 
     bool isInclusiveAncestorOf(const TreeScope&) const;
     unsigned short comparePosition(const TreeScope&) const;
 
     const TreeScope* commonAncestorTreeScope(const TreeScope& other) const;
     TreeScope* commonAncestorTreeScope(TreeScope& other);
 
     Element* getElementByAccessKey(const String& key) const;
 
+    virtual void trace(Visitor*);
+
 protected:
     TreeScope(ContainerNode&, Document&);
     TreeScope(Document&);
     virtual ~TreeScope();
 
     void destroyTreeScopeData();
     void setDocument(Document& document) { m_document = &document; }
     void setParentTreeScope(TreeScope&);
 
     bool hasGuardRefCount() const { return m_guardRefCount; }
 
     void setNeedsStyleRecalcForViewportUnits();
 
 private:
     virtual void dispose() { }
 
     int refCount() const;
 #if SECURITY_ASSERT_ENABLED
     bool deletionHasBegun();
     void beginDeletion();
 #else
     bool deletionHasBegun() { return false; }
     void beginDeletion() { }
 #endif
 
     bool rootNodeHasTreeSharedParent() const;
 
     Node& m_rootNode;
     Document* m_document;
-    TreeScope* m_parentTreeScope;
+    RawPtrWillBeMember<TreeScope> m_parentTreeScope;
     int m_guardRefCount;
 
     OwnPtr<DocumentOrderedMap> m_elementsById;
     OwnPtr<DocumentOrderedMap> m_imageMapsByName;
     OwnPtr<DocumentOrderedMap> m_labelsByForAttribute;
 
     OwnPtr<IdTargetObserverRegistry> m_idTargetObserverRegistry;
 
 #if ENABLE(OILPAN)

[Mads Ager (chromium), 2014/04/24 10:57:36]

All of this code has been removed. There are no more ref counting of tree scopes
and the keep-alive persistent is therefore unused.

     // With Oilpan, a non-zero reference count will keep the TreeScope alive
     // with a self-persistent handle. Whenever the ref count goes above zero
     // we register the TreeScope as a root for garbage collection by allocating a
     // persistent handle to the object itself. When the ref count goes to zero
     // we deallocate the persistent handle again so the object can die if there
     // are no other things keeping it alive.
     //
     // FIXME: Oilpan: Remove m_keepAlive and ref counting and use tracing instead.
     GC_PLUGIN_IGNORE("359444")
     OwnPtr<Persistent<TreeScope> > m_keepAlive;
 #endif
 
     GC_PLUGIN_IGNORE("359444")
     mutable RefPtrWillBePersistent<DOMSelection> m_selection;

[Mads Ager (chromium), 2014/04/24 10:57:36]

This persistent has been removed as well.

 };
 
 inline bool TreeScope::hasElementWithId(StringImpl* id) const
 {
     ASSERT(id);
     return m_elementsById && m_elementsById->contains(id);
 }
 
 inline bool TreeScope::containsMultipleElementsWithId(const AtomicString& id) const
 {
     return m_elementsById && m_elementsById->containsMultiple(id.impl());
 }
 
 inline bool operator==(const TreeScope& a, const TreeScope& b) { return &a == &b; }
 inline bool operator==(const TreeScope& a, const TreeScope* b) { return &a == b; }
 inline bool operator==(const TreeScope* a, const TreeScope& b) { return a == &b; }
 inline bool operator!=(const TreeScope& a, const TreeScope& b) { return !(a == b); }
 inline bool operator!=(const TreeScope& a, const TreeScope* b) { return !(a == b); }
 inline bool operator!=(const TreeScope* a, const TreeScope& b) { return !(a == b); }
 
 HitTestResult hitTestInDocument(const Document*, int x, int y);
 TreeScope* commonTreeScope(Node*, Node*);
 
 } // namespace WebCore
 
 #endif // TreeScope_h