Move //components/test_runner back into //content/shell

components/test_runner/mock_web_audio_device.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 "components/test_runner/mock_web_audio_device.h"
-
-namespace test_runner {
-
-MockWebAudioDevice::MockWebAudioDevice(double sample_rate,
-                                       int frames_per_buffer)
-    : sample_rate_(sample_rate), frames_per_buffer_(frames_per_buffer) {}
-
-MockWebAudioDevice::~MockWebAudioDevice() {}
-
-void MockWebAudioDevice::start() {}
-
-void MockWebAudioDevice::stop() {}
-
-double MockWebAudioDevice::sampleRate() {
-  return sample_rate_;
-}
-
-int MockWebAudioDevice::framesPerBuffer() {
-  return frames_per_buffer_;
-}
-
-}  // namespace test_runner