Add media controls in media notification

third_party/WebKit/Source/modules/mediasession/MediaSession.cpp

 // Copyright 2015 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.
 
 #include "modules/mediasession/MediaSession.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/Event.h"
 #include "core/frame/LocalFrame.h"
 #include "modules/EventTargetModules.h"
 #include "modules/mediasession/MediaMetadata.h"
 #include "modules/mediasession/MediaMetadataSanitizer.h"
+#include "platform/UserGestureIndicator.h"
 #include "public/platform/InterfaceProvider.h"
 #include "wtf/Optional.h"
 #include <memory>
 
 namespace blink {
 
 namespace {
 
 using ::blink::mojom::blink::MediaSessionAction;
 
@@ skipping 116 matching lines @@
           getService(m_scriptState.get())) {
     auto mojomAction = eventNameToMojomAction(eventType);
     DCHECK(mojomAction.has_value());
     service->DisableAction(mojomAction.value());
   }
   return EventTarget::removeEventListenerInternal(eventType, listener, options);
 }
 
 void MediaSession::DidReceiveAction(
     blink::mojom::blink::MediaSessionAction action) {
+  UserGestureIndicator gestureIndicator(UserGestureToken::create());

[whywhat, 2016/10/24 20:54:01]

Have you checked this actually sets the user gesture for the time when the event
is processed? I'd assume dispatchEvent to work asynchronously and
UserGestureIndicator not surviving that.

[mlamouri (slow - plz ping), 2016/10/25 10:38:13]

I think dispatchEvent() is sync, see EventTarget::dispatchEvent()

   dispatchEvent(Event::create(mojomActionToEventName(action)));
 }
 
 DEFINE_TRACE(MediaSession) {
   visitor->trace(m_metadata);
   EventTargetWithInlineData::trace(visitor);
 }
 
 }  // namespace blink