Remove layoutObject() dependency from HTMLPlugInElement::layoutObjectIsFocusable().

third_party/WebKit/Source/core/html/HTMLPlugInElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  *
  * 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 122 matching lines @@
     bool allowedToLoadPlugin(const KURL&, const String& mimeType);
     // Perform checks based on the URL and MIME-type of the object to load.
     bool allowedToLoadObject(const KURL&, const String& mimeType);
     bool wouldLoadAsNetscapePlugin(const String& url, const String& serviceType);
 
     void setPersistedPluginWidget(Widget*);
 
     mutable RefPtr<SharedPersistent<v8::Object>> m_pluginWrapper;
     bool m_needsWidgetUpdate;
     bool m_shouldPreferPlugInsForImages;
+    // Represents |layoutObject() && layoutObject()->isEmbeddedObject() &&
+    // !layoutEmbeddedItem().showsUnavailablePluginIndicator()|.  We want to
+    // avoid to access |layoutObject()| in layoutObjectIsFocusable().
+    bool m_pluginIsAvailable = false;
 
     // Normally the Widget is stored in HTMLFrameOwnerElement::m_widget.
     // However, plugins can persist even when not rendered. In order to
     // prevent confusing code which may assume that widget() != null
     // means the frame is active, we save off m_widget here while
     // the plugin is persisting but not being displayed.
     Member<Widget> m_persistedPluginWidget;
 };
 
 inline bool isHTMLPlugInElement(const HTMLElement& element)
 {
     return element.isPluginElement();
 }
 
 DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(HTMLPlugInElement);
 
 } // namespace blink
 
 #endif // HTMLPlugInElement_h