Oilpan: Move all supplements of Page, Document, and WorkerClients to the managed heap.

Source/web/PrerendererClientImpl.h

 /*
  * Copyright (C) 2012 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 26 matching lines @@
 #include "wtf/PassRefPtr.h"
 
 namespace WebCore {
 class Prerender;
 }
 
 namespace blink {
 
 class WebPrerendererClient;
 
-class PrerendererClientImpl FINAL : public WebCore::PrerendererClient {
+class PrerendererClientImpl FINAL : public NoBaseWillBeGarbageCollected<PrerendererClientImpl>, public WebCore::PrerendererClient {

[haraken, 2014/04/30 02:41:22]

Ditto. You can make PrerendererClient NoBaseWillBeGarbageCollected.

+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(PrerendererClientImpl);
     WTF_MAKE_NONCOPYABLE(PrerendererClientImpl);
 public:
     explicit PrerendererClientImpl(WebPrerendererClient*);
 
     void willAddPrerender(WebCore::Prerender*) OVERRIDE;
 
     virtual void trace(WebCore::Visitor*) OVERRIDE { }
 
 private:
     WebPrerendererClient* m_client;

[haraken, 2014/04/30 02:41:22]

Are you sure that this raw pointer is safe?

Some Impl objects have an OwnPtr to the client (e.g., ServiceWorkerClientImpl).
Some Impl objects have a raw pointer to the client (e.g.,
PrerendererClientImpl). I don't quite understand the difference and why the raw
pointer is safe.

[zerny-chromium, 2014/04/30 08:29:34]

I'm not sure either, but that is orthogonal to this CL as far as I can tell.

[zerny-chromium, 2014/04/30 12:11:26]

Again, here, it is not clear what lifetime guaranties we have for
WebPrerendererClient. It is provided as an input to
WebView::setPrerendererClient(...) which create and attaches the supplement to
the page. The lifetime appears to be external.

 };
 
 }
 
 #endif // PrerendererClientImpl_h