Adds keyboard functionality for videos.

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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MediaControls_h
 #define MediaControls_h
 
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 #include "platform/heap/Visitor.h"
 
 namespace blink {
 
 class Document;
+class Event;
 class HTMLMediaElement;
 class LayoutObject;
 class MediaControlCastButtonElement;
 class MediaControlPanelElement;
 class MediaControlTimelineElement;
 class MediaControlVolumeSliderElement;
 class ShadowRoot;
 
 // MediaControls is an interface to abstract the HTMLMediaElement controls. The
 // implementation will be used using a Factory (see below).
@@ skipping 72 matching lines @@
   virtual void updateCurrentTimeDisplay() = 0;
   virtual void toggleTextTrackList() = 0;
   virtual void showTextTrackAtIndex(unsigned indexToEnable) = 0;
   virtual void disableShowingTextTracks() = 0;
   virtual void enterFullscreen() = 0;
   virtual void exitFullscreen() = 0;
   virtual void showOverlayCastButtonIfNeeded() = 0;
   virtual void toggleOverflowMenu() = 0;
   virtual bool overflowMenuVisible() = 0;
   virtual void onMediaControlsEnabledChange() = 0;
+  virtual void onMediaKeyboardEvent(Event*) = 0;
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   Member<HTMLMediaElement> m_mediaElement;
 };
 
 }  // namespace blink
 
 #endif  // MediaControls_h