Plugin element widget may be a RemoteFrameView.

third_party/WebKit/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 68 matching lines @@
 {
     visitor->trace(m_imageLoader);
     visitor->trace(m_persistedPluginWidget);
     HTMLFrameOwnerElement::trace(visitor);
 }
 
 void HTMLPlugInElement::setPersistedPluginWidget(Widget* widget)
 {
     if (m_persistedPluginWidget == widget)
         return;
-#if ENABLE(OILPAN)
     if (m_persistedPluginWidget) {
         if (m_persistedPluginWidget->isPluginView()) {
             m_persistedPluginWidget->hide();
             m_persistedPluginWidget->dispose();
         } else {
-            ASSERT(m_persistedPluginWidget->isFrameView());
+            ASSERT(m_persistedPluginWidget->isFrameView() || m_persistedPluginWidget->isRemoteFrameView());
         }
     }
-#endif
     m_persistedPluginWidget = widget;
 }
 
 bool HTMLPlugInElement::canProcessDrag() const
 {
     return pluginWidget() && pluginWidget()->isPluginView() && toPluginView(pluginWidget())->canProcessDrag();
 }
 
 bool HTMLPlugInElement::willRespondToMouseClickEvents()
 {
@@ skipping 497 matching lines @@
 
 void HTMLPlugInElement::lazyReattachIfNeeded()
 {
     if (!useFallbackContent() && needsWidgetUpdate() && layoutObject() && !isImageType()) {
         lazyReattachIfAttached();
         setPersistedPluginWidget(nullptr);
     }
 }
 
 } // namespace blink