Improve detection of touch events when hiding media controls.

Source/platform/PlatformMouseEvent.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 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 73 matching lines @@
     }
 
     const IntPoint& position() const { return m_position; }
     const IntPoint& globalPosition() const { return m_globalPosition; }
     const IntPoint& movementDelta() const { return m_movementDelta; }
 
     MouseButton button() const { return m_button; }
     int clickCount() const { return m_clickCount; }
     unsigned modifierFlags() const { return m_modifierFlags; }
     bool fromTouch() const { return m_synthesized == FromTouch; }
+    SyntheticEventType syntheticEventType() const { return m_synthesized; }
 
 protected:
     IntPoint m_position;
     IntPoint m_globalPosition;
     IntPoint m_movementDelta;
     MouseButton m_button;
     int m_clickCount;
     SyntheticEventType m_synthesized;
     unsigned m_modifierFlags;
 };
 
 } // namespace blink
 
 #endif // PlatformMouseEvent_h