Oilpan: move WebPluginLoadObserver to the heap.

third_party/WebKit/Source/web/WebPluginLoadObserver.cpp

 /*
  * Copyright (C) 2009 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 20 matching lines @@
 #include "config.h"
 #include "web/WebPluginLoadObserver.h"
 
 #include "public/web/WebPlugin.h"
 #include "web/WebPluginContainerImpl.h"
 
 namespace blink {
 
 WebPluginLoadObserver::~WebPluginLoadObserver()
 {
-    if (m_pluginContainer)
-        m_pluginContainer->willDestroyPluginLoadObserver(this);
+#if !ENABLE(OILPAN)

[haraken, 2015/11/12 15:51:00]

Can we add ASSERT(!m_pluginContainer) to ENABLE(OILPAN)?

[sof, 2015/11/12 18:15:35]

Don't think so; with this and WebPluginContainerImpl dying at the same time, no
weak processing happens.

+    dispose();
+#endif
+}
+
+void WebPluginLoadObserver::dispose()
+{
+    if (!m_pluginContainer)
+        return;
+
+    m_pluginContainer->willDestroyPluginLoadObserver(this);
+    m_pluginContainer = nullptr;
+}
+
+DEFINE_TRACE(WebPluginLoadObserver)
+{
+    visitor->trace(m_pluginContainer);
 }
 
 void WebPluginLoadObserver::didFinishLoading()
 {
     if (m_pluginContainer)
         m_pluginContainer->plugin()->didFinishLoadingFrameRequest(m_notifyURL, m_notifyData);
 }
 
 void WebPluginLoadObserver::didFailLoading(const WebURLError& error)
 {
     if (m_pluginContainer)
         m_pluginContainer->plugin()->didFailLoadingFrameRequest(m_notifyURL, m_notifyData, error);
 }
 
 } // namespace blink