Standardize usage of virtual/override/final specifiers.

media/base/audio_fifo_unittest.cc

 // Copyright (c) 2012 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.
 
 // TODO(henrika): add test which included |start_frame| in Consume() call.
 
 #include "media/base/audio_fifo.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace media {
 
 class AudioFifoTest : public testing::Test {
  public:
   AudioFifoTest() {}
-  virtual ~AudioFifoTest() {}
+  ~AudioFifoTest() override {}
 
   void VerifyValue(const float data[], int size, float value) {
     for (int i = 0; i < size; ++i)
       ASSERT_FLOAT_EQ(value, data[i]) << "i=" << i;
   }
 
  protected:
   DISALLOW_COPY_AND_ASSIGN(AudioFifoTest);
 };
 
@@ skipping 159 matching lines @@
       VerifyValue(bus->channel(j), bus->channels(), value);
       std::fill(bus->channel(j), bus->channel(j) + bus->frames(), value + 1);
     }
     fifo.Push(bus.get());
     EXPECT_EQ(fifo.frames(), bus->frames());
     ++value;
   }
 }
 
 }  // namespace media