[Media Controls] Add UMA for timeline scrubber

third_party/WebKit/Source/core/html/shadow/MediaControls.h

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Google 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
@@ skipping 206 matching lines @@
   Member<MediaControlDownloadButtonElement> m_downloadButton;
 
   Member<MediaControlsMediaEventListener> m_mediaEventListener;
   Member<MediaControlsWindowEventListener> m_windowEventListener;
   Member<MediaControlsOrientationLockDelegate> m_orientationLockDelegate;
 
   TaskRunnerTimer<MediaControls> m_hideMediaControlsTimer;
   unsigned m_hideTimerBehaviorFlags;
   bool m_isMouseOverControls : 1;
   bool m_isPausedForScrubbing : 1;
+  bool m_hasNeverBeenPlayed : 1;
 
   // Watches the video element for resize and updates media controls as
   // necessary.
   Member<ResizeObserver> m_resizeObserver;
 
   TaskRunnerTimer<MediaControls> m_elementSizeChangedTimer;
   IntSize m_size;
 
   bool m_keepShowingUntilTimerFires : 1;
 };
 
 DEFINE_ELEMENT_TYPE_CASTS(MediaControls, isMediaControls());
 
 }  // namespace blink
 
 #endif