Media Controls: delegate 'volumechange' and 'focusin' handling to an EventListener.

third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

 /*
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 281 matching lines @@
           UserMetricsAction("Media.Controls.Mute"));
 
     mediaElement().setMuted(!mediaElement().muted());
     event->setDefaultHandled();
   }
 
   MediaControlInputElement::defaultEventHandler(event);
 }
 
 void MediaControlMuteButtonElement::updateDisplayType() {
-  setDisplayType(mediaElement().muted() ? MediaUnMuteButton : MediaMuteButton);
+  setDisplayType((mediaElement().muted() || mediaElement().volume() == 0)

[foolip, 2016/11/14 16:07:38]

Why this change? Clicking it will only toggle muted, looking at this I'd expect
it to also change the volume to 1 if it was 0.

[mlamouri (slow - plz ping), 2016/11/14 23:46:29]

Because we actually show a "muted" button if the volume is 0. I will add a
comment explaining. Hopefully, in the long run, this will be cleared out.

Added a comment for this.

+                     ? MediaUnMuteButton
+                     : MediaMuteButton);
   updateOverflowString();
 }
 
 WebLocalizedString::Name
 MediaControlMuteButtonElement::getOverflowStringName() {
   if (mediaElement().muted())
     return WebLocalizedString::OverflowMenuUnmute;
   return WebLocalizedString::OverflowMenuMute;
 }
 
@@ skipping 722 matching lines @@
 MediaControlCurrentTimeDisplayElement*
 MediaControlCurrentTimeDisplayElement::create(MediaControls& mediaControls) {
   MediaControlCurrentTimeDisplayElement* element =
       new MediaControlCurrentTimeDisplayElement(mediaControls);
   element->setShadowPseudoId(
       AtomicString("-webkit-media-controls-current-time-display"));
   return element;
 }
 
 }  // namespace blink