Adds keyboard functionality for videos.

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp

Index: third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp
diff --git a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp
index 402230417b10ac62781469052557d3177e51ee4e..b367c4d1a2e11384842b3a580f97745206c9a812 100644
--- a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp
+++ b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp
@@ -33,6 +33,7 @@
 #include "core/dom/ResizeObserverCallback.h"
 #include "core/dom/ResizeObserverEntry.h"
 #include "core/dom/TaskRunnerHelper.h"
+#include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
@@ -765,6 +766,27 @@ void MediaControlsImpl::defaultEventHandler(Event* event) {
       startHideMediaControlsTimer();
     return;
   }
+
+  if (event->type() == EventTypeNames::input) {
+    resetHideMediaControlsTimer();
+  }

[mlamouri (slow - plz ping), 2017/04/10 13:14:02]

I think steimel@'s CL doing this has landed.

[CJ, 2017/04/12 23:21:05]

Done.

[CJ, 2017/04/12 23:21:05]

Done.

+
+  if (event->isKeyboardEvent()) {
+    const String& key = toKeyboardEvent(event)->key();
+    if (key == "Enter" || toKeyboardEvent(event)->keyCode() == ' ') {
+      m_playButton->onMediaKeyboardEvent(event);
+      return;
+    }
+    if (key == "ArrowLeft" || key == "ArrowRight" || key == "Home" ||
+        key == "End") {
+      timelineElement()->onMediaKeyboardEvent(event);

[mlamouri (slow - plz ping), 2017/04/10 13:14:02]

nit: use the member directly

[CJ, 2017/04/12 23:21:05]

Done.

+      return;
+    }
+    if (key == "ArrowDown" || key == "ArrowUp") {
+      volumeSliderElement()->onMediaKeyboardEvent(event);

[mlamouri (slow - plz ping), 2017/04/10 13:14:02]

ditto

[CJ, 2017/04/12 23:21:05]

Done.

+      return;
+    }
+  }
 }
 
 void MediaControlsImpl::hideMediaControlsTimerFired(TimerBase*) {