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 df272a9493bee9dd77330ad7c5154beb82b50715..70734c0bf99eeb0dbdf68ae4c3a4755c14d5c413 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
@@ -120,6 +120,8 @@ class MediaControlPlayButtonElement final : public MediaControlInputElement {
 
   bool hasOverflowButton() override { return true; }
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlPlayButtonElement(MediaControls&);
 
@@ -273,6 +275,8 @@ class MediaControlTimelineElement final : public MediaControlInputElement {
   void setPosition(double);
   void setDuration(double);
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlTimelineElement(MediaControls&);
 
@@ -354,6 +358,8 @@ class MediaControlVolumeSliderElement final : public MediaControlInputElement {
   bool willRespondToMouseClickEvents() override;
   void setVolume(double);
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }
+
  private:
   explicit MediaControlVolumeSliderElement(MediaControls&);