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

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

Index: third_party/WebKit/Source/core/html/HTMLPlugInElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLPlugInElement.h b/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
index 5459be0611818aa7313e2d5f5943d35dd268bec3..8b91487abf2673dc6bfe19e2419276590842194a 100644
--- a/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
@@ -140,6 +140,10 @@ private:
     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