Start separating the text track container from the media controls

Source/core/dom/Node.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2011, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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
@@ skipping 240 matching lines @@
     CustomElementState customElementState() const
     {
         return isCustomElement()
             ? (getFlag(CustomElementUpgradedFlag) ? Upgraded : WaitingForUpgrade)
             : NotCustomElement;
     }
     void setCustomElementState(CustomElementState newState);
 
     virtual bool isMediaControlElement() const { return false; }
     virtual bool isMediaControls() const { return false; }
+    virtual bool isTextTrackContainer() const { return false; }
     virtual bool isVTTElement() const { return false; }
     virtual bool isAttributeNode() const { return false; }
     virtual bool isCharacterDataNode() const { return false; }
     virtual bool isFrameOwnerElement() const { return false; }
 
     // StyledElements allow inline style (style="border: 1px"), presentational attributes (ex. color),
     // class names (ex. class="foo bar") and other non-basic styling features. They and also control
     // if this element can participate in style sharing.
     //
     // FIXME: The only things that ever go through StyleResolver that aren't StyledElements are
@@ skipping 630 matching lines @@
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showNode(const blink::Node*);
 void showTree(const blink::Node*);
 void showNodePath(const blink::Node*);
 #endif
 
 #endif // Node_h