Adds keyboard functionality for videos.

third_party/WebKit/Source/modules/media_controls/elements/MediaControlTimelineElement.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 MediaControlTimelineElement_h
 #define MediaControlTimelineElement_h
 
 #include "core/html/shadow/MediaControlElementTypes.h"
 #include "modules/media_controls/elements/MediaControlTimelineMetrics.h"
 
 namespace blink {
 
 class Event;
 class MediaControlsImpl;
 
 class MediaControlTimelineElement final : public MediaControlInputElement {
  public:
   explicit MediaControlTimelineElement(MediaControlsImpl&);
 
   // MediaControlInputElement overrides.
   bool WillRespondToMouseClickEvents() override;
 
   // FIXME: An "earliest possible position" will be needed once that concept
   // is supported by HTMLMediaElement, see https://crbug.com/137275
   void SetPosition(double);
   void SetDuration(double);
 
   void OnPlaying();
 
+  void OnMediaKeyboardEvent(Event* event) { DefaultEventHandler(event); }
+
  private:
   void DefaultEventHandler(Event*) override;
   bool KeepEventInNode(Event*) override;
 
   // Width in CSS pixels * pageZoomFactor (ignores CSS transforms for
   // simplicity; deliberately ignores pinch zoom's pageScaleFactor).
   int TimelineWidth();
 
   MediaControlTimelineMetrics metrics_;
 };
 
 }  // namespace blink
 
 #endif  // MediaControlTimelineElement