Standardize usage of virtual/override/final in content/

content/shell/renderer/test_runner/mock_web_media_stream_center.cc

 // Copyright 2014 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 "content/shell/renderer/test_runner/mock_web_media_stream_center.h"
 
 #include "base/logging.h"
 #include "content/shell/renderer/test_runner/test_interfaces.h"
 #include "content/shell/renderer/test_runner/web_test_delegate.h"
 #include "third_party/WebKit/public/platform/WebAudioDestinationConsumer.h"
@@ skipping 10 matching lines @@
 
 namespace {
 class NewTrackTask : public WebMethodTask<MockWebMediaStreamCenter> {
  public:
   NewTrackTask(MockWebMediaStreamCenter* object,
                const blink::WebMediaStream& stream)
       : WebMethodTask<MockWebMediaStreamCenter>(object), stream_(stream) {
     DCHECK(!stream_.isNull());
   }
 
-  virtual ~NewTrackTask() {}
+  ~NewTrackTask() override {}
 
-  virtual void RunIfValid() override {
+  void RunIfValid() override {
     blink::WebMediaStreamSource source;
     blink::WebMediaStreamTrack track;
     source.initialize("MagicVideoDevice#1",
                       blink::WebMediaStreamSource::TypeVideo,
                       "Magic video track");
     track.initialize(source);
     stream_.addTrack(track);
   }
 
  private:
@@ skipping 83 matching lines @@
   interfaces_->GetDelegate()->PostTask(new NewTrackTask(this, stream));
 }
 
 blink::WebAudioSourceProvider*
 MockWebMediaStreamCenter::createWebAudioSourceFromMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
   return NULL;
 }
 
 }  // namespace content