Oilpan: make shutdown of plugin container objects work better.

Source/core/html/HTMLPlugInElement.cpp

 /**
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 15 matching lines @@
 #include "bindings/v8/ScriptController.h"
 #include "bindings/v8/npruntime_impl.h"
 #include "core/CSSPropertyNames.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Node.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/events/Event.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/Settings.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/html/HTMLContentElement.h"
 #include "core/html/HTMLImageLoader.h"
 #include "core/html/PluginDocument.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/EventHandler.h"
 #include "core/page/Page.h"
-#include "core/frame/Settings.h"
 #include "core/plugins/PluginView.h"
 #include "core/rendering/RenderEmbeddedObject.h"
 #include "core/rendering/RenderImage.h"
 #include "core/rendering/RenderWidget.h"
 #include "platform/Logging.h"
 #include "platform/MIMETypeFromURL.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/Widget.h"
 #include "platform/plugins/PluginData.h"
 
@@ skipping 140 matching lines @@
         setNeedsWidgetUpdate(true);
     if (m_isDelayingLoadEvent) {
         m_isDelayingLoadEvent = false;
         document().decrementLoadEventDelayCount();
     }
 
     // Only try to persist a plugin widget we actually own.
     Widget* plugin = ownedWidget();
     if (plugin && plugin->pluginShouldPersist())
         m_persistedPluginWidget = plugin;
+#if ENABLE(OILPAN)
+    else if (plugin)
+        plugin->detach();
+#endif
     resetInstance();
     // FIXME - is this next line necessary?
     setWidget(nullptr);
 
     if (m_isCapturingMouseEvents) {
         if (LocalFrame* frame = document().frame())
             frame->eventHandler().setCapturingMouseEventsNode(nullptr);
         m_isCapturingMouseEvents = false;
     }
 
@@ skipping 358 matching lines @@
 {
     return false;
 }
 
 bool HTMLPlugInElement::useFallbackContent() const
 {
     return hasAuthorShadowRoot();
 }
 
 }