[Oilpan] Replace a raw pointer with UntracedMember in RetainedDOMInfo

third_party/WebKit/Source/bindings/core/v8/RetainedDOMInfo.h

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 39 matching lines @@
     const char* GetGroupLabel() override;
     const char* GetLabel() override;
     intptr_t GetElementCount() override;
     intptr_t GetEquivalenceClass() override;
 
     static v8::RetainedObjectInfo* retainedDOMInfo(uint16_t classId, v8::Local<v8::Value> wrapper);
 
 private:
     // V8 guarantees to keep RetainedObjectInfos alive only during a GC or heap snapshotting round, when renderer
     // doesn't get control. This allows us to use raw pointers.
-    GC_PLUGIN_IGNORE("553613")
-    Node* m_root;
+    RawPtrWillBeUntracedMember<Node> m_root;

[haraken, 2015/11/27 05:11:11]

Yes, this pointer is pretty special (as commented above) so it makes sense to
use an UntracedMember here.

 };
 
 class ActiveDOMObjectsInfo final : public RetainedObjectInfo {
 public:
     explicit ActiveDOMObjectsInfo(int numberOfObjectsWithPendingActivity);
     ~ActiveDOMObjectsInfo() override;
     void Dispose() override;
     bool IsEquivalent(v8::RetainedObjectInfo* other) override;
     intptr_t GetHash() override;
     const char* GetGroupLabel() override;
     const char* GetLabel() override;
     intptr_t GetElementCount() override;
     intptr_t GetEquivalenceClass() override;
 
 private:
     int m_numberOfObjectsWithPendingActivity;
 };
 
 } // namespace blink
 
 #endif // RetainedDOMInfo_h