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 eaf89e2ddccf9e9711b8306d09939f5a6bc961b1..3d843a7e52c04568d39dc1f2c67ee33b7004594e 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
@@ -82,6 +82,8 @@ class CORE_EXPORT MediaControlPlayButtonElement final
 
   bool HasOverflowButton() override { return true; }
 
+  void OnMediaKeyboardEvent(Event* event) { DefaultEventHandler(event); }
+
  private:
   explicit MediaControlPlayButtonElement(MediaControls&);
 
@@ -239,6 +241,8 @@ class CORE_EXPORT MediaControlTimelineElement final
 
   void OnPlaying();
 
+  void onMediaKeyboardEvent(Event* event) { DefaultEventHandler(event); }
+
  private:
   explicit MediaControlTimelineElement(MediaControls&);
 
@@ -329,6 +333,8 @@ class CORE_EXPORT MediaControlVolumeSliderElement final
   bool WillRespondToMouseClickEvents() override;
   void SetVolume(double);
 
+  void onMediaKeyboardEvent(Event* event) { DefaultEventHandler(event); }
+
  private:
   explicit MediaControlVolumeSliderElement(MediaControls&);