Standardize usage of virtual/override/final specifiers.

content/renderer/media/media_stream_video_track_unittest.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 "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 20 matching lines @@
   MediaStreamVideoTrackTest()
       : child_process_(new ChildProcess()),
         mock_source_(new MockMediaStreamVideoSource(false)),
         source_started_(false) {
     blink_source_.initialize(base::UTF8ToUTF16("dummy_source_id"),
                               blink::WebMediaStreamSource::TypeVideo,
                               base::UTF8ToUTF16("dummy_source_name"));
     blink_source_.setExtraData(mock_source_);
   }
 
-  virtual ~MediaStreamVideoTrackTest() {
-  }
+  ~MediaStreamVideoTrackTest() override {}
 
-  virtual void TearDown() override {
+  void TearDown() override {
     blink_source_.reset();
     blink::WebHeap::collectAllGarbageForTesting();
   }
 
   void DeliverVideoFrameAndWaitForRenderer(MockMediaStreamVideoSink* sink) {
     base::RunLoop run_loop;
     base::Closure quit_closure = run_loop.QuitClosure();
     EXPECT_CALL(*sink, OnVideoFrame()).WillOnce(
         RunClosure(quit_closure));
     scoped_refptr<media::VideoFrame> frame =
@@ skipping 174 matching lines @@
   MediaStreamVideoTrack* native_track2 =
         MediaStreamVideoTrack::GetVideoTrack(track2);
   native_track2->Stop();
   EXPECT_EQ(blink::WebMediaStreamSource::ReadyStateEnded, sink2.state());
   EXPECT_EQ(blink::WebMediaStreamSource::ReadyStateEnded,
             blink_source().readyState());
   MediaStreamVideoSink::RemoveFromVideoTrack(&sink2, track2);
 }
 
 }  // namespace content