Implement <video controls> dodging for text track layout

Source/core/html/HTMLMediaElement.h

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 218 matching lines @@
     void setClosedCaptionsVisible(bool);
 
     void remoteRouteAvailabilityChanged(bool);
     void connectedToRemoteDevice();
     void disconnectedFromRemoteDevice();
 
     // Returns the MediaControls, or null if they have not been added yet.
     // Note that this can be non-null even if there is no controls attribute.
     MediaControls* mediaControls() const;
 
+    // Notifies the media element that the media controls became visible, so
+    // that text track layout may be updated to avoid overlapping them.
+    void mediaControlsDidBecomeVisible();
+
     void sourceWasRemoved(HTMLSourceElement*);
     void sourceWasAdded(HTMLSourceElement*);
 
     // ActiveDOMObject functions.
     virtual bool hasPendingActivity() const override final;
     virtual void contextDestroyed() override final;
 
 #if ENABLE(WEB_AUDIO)
     AudioSourceProviderClient* audioSourceNode() { return m_audioSourceNode; }
     void setAudioSourceNode(AudioSourceProviderClient*);
@@ skipping 332 matching lines @@
 inline bool isHTMLMediaElement(const HTMLElement& element)
 {
     return isHTMLAudioElement(element) || isHTMLVideoElement(element);
 }
 
 DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(HTMLMediaElement);
 
 } // namespace blink
 
 #endif // HTMLMediaElement_h