Prefer ContextClient mixin over manual ExecutionContext handling.

third_party/WebKit/Source/modules/mediastream/MediaStream.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Ericsson AB. 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 21 matching lines @@
 #include "modules/ModulesExport.h"
 #include "modules/mediastream/MediaStreamTrack.h"
 #include "platform/Timer.h"
 #include "platform/mediastream/MediaStreamDescriptor.h"
 
 namespace blink {
 
 class ExceptionState;
 
 class MODULES_EXPORT MediaStream final : public EventTargetWithInlineData,
+                                         public ContextClient,
                                          public URLRegistrable,
                                          public MediaStreamDescriptorClient {
   USING_GARBAGE_COLLECTED_MIXIN(MediaStream);
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   static MediaStream* create(ExecutionContext*);
   static MediaStream* create(ExecutionContext*, MediaStream*);
   static MediaStream* create(ExecutionContext*, const MediaStreamTrackVector&);
   static MediaStream* create(ExecutionContext*, MediaStreamDescriptor*);
@@ skipping 20 matching lines @@
   void trackEnded();
 
   // MediaStreamDescriptorClient
   void streamEnded() override;
 
   MediaStreamDescriptor* descriptor() const { return m_descriptor; }
 
   // EventTarget
   const AtomicString& interfaceName() const override;
   ExecutionContext* getExecutionContext() const override {
-    return m_executionContext;
+    return ContextClient::getExecutionContext();
   }
 
   // URLRegistrable
   URLRegistry& registry() const override;
 
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   bool addEventListenerInternal(
       const AtomicString& eventType,
@@ skipping 14 matching lines @@
 
   void scheduleDispatchEvent(Event*);
   void scheduledEventTimerFired(TimerBase*);
 
   MediaStreamTrackVector m_audioTracks;
   MediaStreamTrackVector m_videoTracks;
   Member<MediaStreamDescriptor> m_descriptor;
 
   Timer<MediaStream> m_scheduledEventTimer;
   HeapVector<Member<Event>> m_scheduledEvents;
-  Member<ExecutionContext> m_executionContext;
 };
 
-typedef HeapVector<Member<MediaStream>> MediaStreamVector;
+using MediaStreamVector = HeapVector<Member<MediaStream>>;
 
 MediaStream* toMediaStream(MediaStreamDescriptor*);
 
 }  // namespace blink
 
 #endif  // MediaStream_h