Adds keyboard functionality for videos.

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

Index: third_party/WebKit/Source/core/html/shadow/MediaControls.h
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControls.h b/third_party/WebKit/Source/core/html/shadow/MediaControls.h
index 590db6ed0005814993ba95c843bdc2d4848023c6..67a1a0e1748a6aed6dd4e6281f3b97e987e30a14 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControls.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControls.h
@@ -119,6 +119,8 @@ class CORE_EXPORT MediaControls final : public HTMLDivElement {
     refreshCastButtonVisibilityWithoutUpdate();
   }
 
+  void onMediaKeyboardEvent(Event* event) { defaultEventHandler(event); }

[mlamouri (slow - plz ping), 2017/03/27 13:02:12]

Can you move this in the block that starts with the "// Methods called by
MediaControlsMediaEventListener" comment?

Also maybe call it "onKeyPress" to make it generic. MediaControls could re-use
this for other stuff.

Finally, what about having our own handler for this with the `key` sent back.

[CJ, 2017/04/08 00:31:27]

Done.

+
   DECLARE_VIRTUAL_TRACE();
 
  private: