Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/accessibility/AXObjectCache.cpp

 /*
  * Copyright (C) 2008, 2009, 2010 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 553 matching lines @@
 void AXObjectCache::remove(AbstractInlineTextBox* inlineTextBox)
 {
     if (!inlineTextBox)
         return;
 
     AXID axID = m_inlineTextBoxObjectMapping.get(inlineTextBox);
     remove(axID);
     m_inlineTextBoxObjectMapping.remove(inlineTextBox);
 }
 
+// FIXME: Oilpan: Use a weak hashmap for this instead.
+void AXObjectCache::clearWeakMembers(Visitor* visitor)
+{
+    Vector<Node*> deadNodes;
+    for (HashMap<Node*, AXID>::iterator it = m_nodeObjectMapping.begin(); it != m_nodeObjectMapping.end(); ++it) {
+        if (!visitor->isAlive(it->key))
+            deadNodes.append(it->key);
+    }
+    for (unsigned i = 0; i < deadNodes.size(); ++i)
+        remove(deadNodes[i]);
+}
+
 AXID AXObjectCache::platformGenerateAXID() const
 {
     static AXID lastUsedID = 0;
 
     // Generate a new ID.
     AXID objID = lastUsedID;
     do {
         ++objID;
     } while (!objID || HashTraits<AXID>::isDeletedValue(objID) || m_idsInUse.contains(objID));
 
@@ skipping 416 matching lines @@
 {
     postPlatformNotification(getOrCreate(scrollView), AXScrollPositionChanged);
 }
 
 void AXObjectCache::handleScrollPositionChanged(RenderObject* renderObject)
 {
     postPlatformNotification(getOrCreate(renderObject), AXScrollPositionChanged);
 }
 
 } // namespace WebCore