Adds keyboard functionality for videos.

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

Index: third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
index 57cd951499cef4add92f1f0a75b713134210b635..f8eafc416aa2899ebac2d7803f40b9472f326321 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
@@ -124,6 +124,8 @@ class CORE_EXPORT MediaControlPlayButtonElement final
 
   bool hasOverflowButton() override { return true; }
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlPlayButtonElement(MediaControls&);
 
@@ -279,6 +281,8 @@ class CORE_EXPORT MediaControlTimelineElement final
   void setPosition(double);
   void setDuration(double);
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlTimelineElement(MediaControls&);
 
@@ -362,6 +366,8 @@ class CORE_EXPORT MediaControlVolumeSliderElement final
   bool willRespondToMouseClickEvents() override;
   void setVolume(double);
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlVolumeSliderElement(MediaControls&);