Delete AudioOutputMixer.

Not used.  If we do enable browser side mixing in the future it'll
be based on AudioConverter.  With renderer side mixing and
AudioOutputProxy, there's not a pressing need for this function.

BUG=none
TEST=compile


Review URL: https://chromiumcodereview.appspot.com/12082111

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@180072 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 0 insertions, 730 deletions

diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index a12b243..67e03c0 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -19,12 +19,6 @@
 #include "media/audio/virtual_audio_output_stream.h"
 #include "media/base/media_switches.h"
 
-// TODO(dalecurtis): Temporarily disabled while switching pipeline to use float,
-// http://crbug.com/114700
-#if defined(ENABLE_AUDIO_MIXER)
-#include "media/audio/audio_output_mixer.h"
-#endif
-
 namespace media {
 
 static const int kStreamCloseDelaySeconds = 5;
@@ -272,18 +266,6 @@ AudioOutputStream* AudioManagerBase::MakeAudioOutputStreamProxy(
     return new AudioOutputProxy(dispatcher);
   }
 
-#if defined(ENABLE_AUDIO_MIXER)
-  // TODO(dalecurtis): Browser side mixing has a couple issues that must be
-  // fixed before it can be turned on by default: http://crbug.com/138098 and
-  // http://crbug.com/140247
-  if (cmd_line->HasSwitch(switches::kEnableAudioMixer)) {
-    scoped_refptr<AudioOutputDispatcher> dispatcher =
-        new AudioOutputMixer(this, params, close_delay);
-    output_dispatchers_[dispatcher_key] = dispatcher;
-    return new AudioOutputProxy(dispatcher);
-  }
-#endif
-
   scoped_refptr<AudioOutputDispatcher> dispatcher =
       new AudioOutputDispatcherImpl(this, output_params, close_delay);
   output_dispatchers_[dispatcher_key] = dispatcher;
diff --git a/media/audio/audio_output_mixer.cc b/media/audio/audio_output_mixer.cc
deleted file mode 100644
index edce4ea..0000000
--- a/media/audio/audio_output_mixer.cc
+++ /dev/null
@@ -1,248 +0,0 @@
-// 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.
-
-#include "media/audio/audio_output_mixer.h"
-
-#include <algorithm>
-
-#include "base/bind.h"
-#include "base/compiler_specific.h"
-#include "base/message_loop.h"
-#include "base/time.h"
-#include "media/audio/audio_io.h"
-#include "media/audio/audio_output_proxy.h"
-#include "media/audio/audio_util.h"
-
-namespace media {
-
-AudioOutputMixer::AudioOutputMixer(AudioManager* audio_manager,
-                                   const AudioParameters& params,
-                                   const base::TimeDelta& close_delay)
-    : AudioOutputDispatcher(audio_manager, params),
-      ALLOW_THIS_IN_INITIALIZER_LIST(weak_this_(this)),
-      close_timer_(FROM_HERE,
-                   close_delay,
-                   weak_this_.GetWeakPtr(),
-                   &AudioOutputMixer::ClosePhysicalStream),
-      pending_bytes_(0) {
-  // TODO(enal): align data.
-  mixer_data_.reset(new uint8[params_.GetBytesPerBuffer()]);
-}
-
-AudioOutputMixer::~AudioOutputMixer() {
-}
-
-bool AudioOutputMixer::OpenStream() {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  if (physical_stream_.get())
-    return true;
-  AudioOutputStream* stream = audio_manager_->MakeAudioOutputStream(params_);
-  if (!stream)
-    return false;
-  if (!stream->Open()) {
-    stream->Close();
-    return false;
-  }
-  pending_bytes_ = 0;  // Just in case.
-  physical_stream_.reset(stream);
-  close_timer_.Reset();
-  return true;
-}
-
-bool AudioOutputMixer::StartStream(
-    AudioOutputStream::AudioSourceCallback* callback,
-    AudioOutputProxy* stream_proxy) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  // May need to re-open the physical stream if no active proxies and
-  // enough time had pass.
-  OpenStream();
-  if (!physical_stream_.get())
-    return false;
-
-  double volume = 0.0;
-  stream_proxy->GetVolume(&volume);
-  bool should_start = proxies_.empty();
-  {
-    base::AutoLock lock(lock_);
-    ProxyData* proxy_data = &proxies_[stream_proxy];
-    proxy_data->audio_source_callback = callback;
-    proxy_data->volume = volume;
-    proxy_data->pending_bytes = 0;
-  }
-  // We cannot start physical stream under the lock,
-  // OnMoreData() would try acquiring it...
-  if (should_start) {
-    physical_stream_->SetVolume(1.0);
-    physical_stream_->Start(this);
-  }
-  return true;
-}
-
-void AudioOutputMixer::StopStream(AudioOutputProxy* stream_proxy) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  // Because of possible deadlock we cannot stop physical stream under the lock
-  // (physical_stream_->Stop() can call OnError(), and it acquires the lock to
-  // iterate through proxies), so acquire the lock, update proxy list, release
-  // the lock, and only then stop physical stream if necessary.
-  bool stop_physical_stream = false;
-  {
-    base::AutoLock lock(lock_);
-    ProxyMap::iterator it = proxies_.find(stream_proxy);
-    if (it != proxies_.end()) {
-      proxies_.erase(it);
-      stop_physical_stream = proxies_.empty();
-    }
-  }
-  if (physical_stream_.get()) {
-    if (stop_physical_stream) {
-      physical_stream_->Stop();
-      pending_bytes_ = 0;  // Just in case.
-    }
-    close_timer_.Reset();
-  }
-}
-
-void AudioOutputMixer::StreamVolumeSet(AudioOutputProxy* stream_proxy,
-                                       double volume) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  ProxyMap::iterator it = proxies_.find(stream_proxy);
-
-  // Do nothing if stream is not currently playing.
-  if (it != proxies_.end()) {
-    base::AutoLock lock(lock_);
-    it->second.volume = volume;
-  }
-}
-
-void AudioOutputMixer::CloseStream(AudioOutputProxy* stream_proxy) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  StopStream(stream_proxy);
-}
-
-void AudioOutputMixer::Shutdown() {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  // Cancel any pending tasks to close physical stream.
-  weak_this_.InvalidateWeakPtrs();
-
-  while (!proxies_.empty()) {
-    CloseStream(proxies_.begin()->first);
-  }
-  ClosePhysicalStream();
-
-  // No AudioOutputProxy objects should hold a reference to us when we get
-  // to this stage.
-  DCHECK(HasOneRef()) << "Only the AudioManager should hold a reference";
-}
-
-void AudioOutputMixer::ClosePhysicalStream() {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
-
-  if (proxies_.empty() && physical_stream_.get() != NULL)
-    physical_stream_.release()->Close();
-}
-
-// AudioSourceCallback implementation.
-uint32 AudioOutputMixer::OnMoreData(uint8* dest,
-                                    uint32 max_size,
-                                    AudioBuffersState buffers_state) {
-  max_size = std::min(max_size,
-                      static_cast<uint32>(params_.GetBytesPerBuffer()));
-  // TODO(enal): consider getting rid of lock as it is in time-critical code.
-  //             E.g. swap |proxies_| with local variable, and merge 2 lists
-  //             at the end. That would speed things up but complicate stopping
-  //             the stream.
-  base::AutoLock lock(lock_);
-
-  DCHECK_GE(pending_bytes_, buffers_state.pending_bytes);
-  if (proxies_.empty()) {
-    pending_bytes_ = buffers_state.pending_bytes;
-    return 0;
-  }
-  uint32 actual_total_size = 0;
-  uint32 bytes_per_sample = params_.bits_per_sample() >> 3;
-
-  // Go through all the streams, getting data for every one of them
-  // and mixing it into destination.
-  // Minor optimization: for the first stream we are writing data directly into
-  // destination. This way we don't have to mix the data when there is only one
-  // active stream, and net win in other cases, too.
-  bool first_stream = true;
-  uint8* actual_dest = dest;
-  for (ProxyMap::iterator it = proxies_.begin(); it != proxies_.end(); ++it) {
-    ProxyData* proxy_data = &it->second;
-
-    // If proxy's pending bytes are the same as pending bytes for combined
-    // stream, both are either pre-buffering or in the steady state. In either
-    // case new pending bytes for proxy is the same as new pending bytes for
-    // combined stream.
-    // Note: use >= instead of ==, that way is safer.
-    if (proxy_data->pending_bytes >= pending_bytes_)
-      proxy_data->pending_bytes = buffers_state.pending_bytes;
-
-    // Note: there is no way we can deduce hardware_delay_bytes for the
-    // particular proxy stream. Use zero instead.
-    uint32 actual_size = proxy_data->audio_source_callback->OnMoreData(
-        actual_dest,
-        max_size,
-        AudioBuffersState(proxy_data->pending_bytes, 0));
-    if (actual_size == 0)
-      continue;
-    double volume = proxy_data->volume;
-
-    // Different handling for first and all subsequent streams.
-    if (first_stream) {
-      if (volume != 1.0) {
-        media::AdjustVolume(actual_dest,
-                            actual_size,
-                            params_.channels(),
-                            bytes_per_sample,
-                            volume);
-      }
-      if (actual_size < max_size)
-        memset(dest + actual_size, 0, max_size - actual_size);
-      first_stream = false;
-      actual_dest = mixer_data_.get();
-      actual_total_size = actual_size;
-    } else {
-      media::MixStreams(dest,
-                        actual_dest,
-                        actual_size,
-                        bytes_per_sample,
-                        volume);
-      actual_total_size = std::max(actual_size, actual_total_size);
-    }
-  }
-
-  // Now go through all proxies once again and increase pending_bytes
-  // for each proxy. Could not do it earlier because we did not know
-  // actual_total_size.
-  for (ProxyMap::iterator it = proxies_.begin(); it != proxies_.end(); ++it) {
-    it->second.pending_bytes += actual_total_size;
-  }
-  pending_bytes_ = buffers_state.pending_bytes + actual_total_size;
-
-  return actual_total_size;
-}
-
-void AudioOutputMixer::OnError(AudioOutputStream* stream, int code) {
-  base::AutoLock lock(lock_);
-  for (ProxyMap::iterator it = proxies_.begin(); it != proxies_.end(); ++it) {
-    it->second.audio_source_callback->OnError(it->first, code);
-  }
-}
-
-void AudioOutputMixer::WaitTillDataReady() {
-  base::AutoLock lock(lock_);
-  for (ProxyMap::iterator it = proxies_.begin(); it != proxies_.end(); ++it) {
-    it->second.audio_source_callback->WaitTillDataReady();
-  }
-}
-
-}  // namespace media
diff --git a/media/audio/audio_output_mixer.h b/media/audio/audio_output_mixer.h
deleted file mode 100644
index 4ddeeef..0000000
--- a/media/audio/audio_output_mixer.h
+++ /dev/null
@@ -1,94 +0,0 @@
-// 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.
-
-// AudioOutputMixer is a class that implements browser-side audio mixer.
-// AudioOutputMixer implements both AudioOutputDispatcher and
-// AudioSourceCallback interfaces.
-
-#ifndef MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_
-#define MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_
-
-#include <map>
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/synchronization/lock.h"
-#include "base/timer.h"
-#include "media/audio/audio_io.h"
-#include "media/audio/audio_manager.h"
-#include "media/audio/audio_output_dispatcher.h"
-#include "media/audio/audio_parameters.h"
-
-namespace media {
-
-class MEDIA_EXPORT AudioOutputMixer
-    : public AudioOutputDispatcher,
-      public AudioOutputStream::AudioSourceCallback {
- public:
-  AudioOutputMixer(AudioManager* audio_manager,
-                   const AudioParameters& params,
-                   const base::TimeDelta& close_delay);
-
-  // AudioOutputDispatcher interface.
-  virtual bool OpenStream() OVERRIDE;
-  virtual bool StartStream(AudioOutputStream::AudioSourceCallback* callback,
-                           AudioOutputProxy* stream_proxy) OVERRIDE;
-  virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE;
-  virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy,
-                               double volume) OVERRIDE;
-  virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE;
-  virtual void Shutdown() OVERRIDE;
-
-  // AudioSourceCallback interface.
-  virtual uint32 OnMoreData(uint8* dest,
-                            uint32 max_size,
-                            AudioBuffersState buffers_state) OVERRIDE;
-  virtual void OnError(AudioOutputStream* stream, int code) OVERRIDE;
-  virtual void WaitTillDataReady() OVERRIDE;
-
- private:
-  friend class base::RefCountedThreadSafe<AudioOutputMixer>;
-  virtual ~AudioOutputMixer();
-
-  // Called by |close_timer_|. Closes physical stream.
-  void ClosePhysicalStream();
-
-  // The |lock_| must be acquired whenever we modify |proxies_| in the audio
-  // manager thread or accessing it in the hardware audio thread. Read in the
-  // audio manager thread is safe.
-  base::Lock lock_;
-
-  // List of audio output proxies currently being played.
-  // For every proxy we store aux structure containing data necessary for
-  // mixing.
-  struct ProxyData {
-    AudioOutputStream::AudioSourceCallback* audio_source_callback;
-    double volume;
-    int pending_bytes;
-  };
-  typedef std::map<AudioOutputProxy*, ProxyData> ProxyMap;
-  ProxyMap proxies_;
-
-  // Physical stream for this mixer.
-  scoped_ptr<AudioOutputStream> physical_stream_;
-
-  // Temporary buffer used when mixing. Allocated in the constructor
-  // to avoid constant allocation/deallocation in the callback.
-  scoped_array<uint8> mixer_data_;
-
-  // Used to post delayed tasks to ourselves that we cancel inside Shutdown().
-  base::WeakPtrFactory<AudioOutputMixer> weak_this_;
-  base::DelayTimer<AudioOutputMixer> close_timer_;
-
-  // Size of data in all in-flight buffers.
-  int pending_bytes_;
-
-  DISALLOW_COPY_AND_ASSIGN(AudioOutputMixer);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_
diff --git a/media/audio/audio_output_proxy_unittest.cc b/media/audio/audio_output_proxy_unittest.cc
index 6c13856..fdebdab 100644
--- a/media/audio/audio_output_proxy_unittest.cc
+++ b/media/audio/audio_output_proxy_unittest.cc
@@ -17,12 +17,6 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-// TODO(dalecurtis): Temporarily disabled while switching pipeline to use float,
-// http://crbug.com/114700
-#if defined(ENABLE_AUDIO_MIXER)
-#include "media/audio/audio_output_mixer.h"
-#endif
-
 using ::testing::_;
 using ::testing::AllOf;
 using ::testing::DoAll;
@@ -169,9 +163,6 @@ class AudioOutputProxyTest : public testing::Test {
     dispatcher_impl_ = new AudioOutputDispatcherImpl(&manager(),
                                                      params_,
                                                      close_delay);
-#if defined(ENABLE_AUDIO_MIXER)
-    mixer_ = new AudioOutputMixer(&manager(), params_, close_delay);
-#endif
 
     // Necessary to know how long the dispatcher will wait before posting
     // StopStreamTask.
@@ -450,9 +441,6 @@ class AudioOutputProxyTest : public testing::Test {
 
   MessageLoop message_loop_;
   scoped_refptr<AudioOutputDispatcherImpl> dispatcher_impl_;
-#if defined(ENABLE_AUDIO_MIXER)
-  scoped_refptr<AudioOutputMixer> mixer_;
-#endif
   base::TimeDelta pause_delay_;
   MockAudioManager manager_;
   MockAudioSourceCallback callback_;
@@ -494,13 +482,6 @@ TEST_F(AudioOutputProxyTest, CreateAndClose) {
   proxy->Close();
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, CreateAndClose_Mixer) {
-  AudioOutputProxy* proxy = new AudioOutputProxy(mixer_);
-  proxy->Close();
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, CreateAndClose) {
   AudioOutputProxy* proxy = new AudioOutputProxy(resampler_);
   proxy->Close();
@@ -510,12 +491,6 @@ TEST_F(AudioOutputProxyTest, OpenAndClose) {
   OpenAndClose(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, OpenAndClose_Mixer) {
-  OpenAndClose(mixer_);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, OpenAndClose) {
   OpenAndClose(resampler_);
 }
@@ -536,12 +511,6 @@ TEST_F(AudioOutputProxyTest, StartAndStop) {
   StartAndStop(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, StartAndStop_Mixer) {
-  StartAndStop(mixer_);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, StartAndStop) {
   StartAndStop(resampler_);
 }
@@ -550,12 +519,6 @@ TEST_F(AudioOutputProxyTest, CloseAfterStop) {
   CloseAfterStop(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, CloseAfterStop_Mixer) {
-  CloseAfterStop(mixer_);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, CloseAfterStop) {
   CloseAfterStop(resampler_);
 }
@@ -564,12 +527,6 @@ TEST_F(AudioOutputProxyTest, TwoStreams) {
   TwoStreams(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, TwoStreams_Mixer) {
-  TwoStreams(mixer_);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, TwoStreams) {
   TwoStreams(resampler_);
 }
@@ -581,41 +538,6 @@ TEST_F(AudioOutputProxyTest, TwoStreams_OnePlaying) {
   TwoStreams_OnePlaying(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-// Two streams: verify that only one device will be created.
-TEST_F(AudioOutputProxyTest, TwoStreams_OnePlaying_Mixer) {
-  MockAudioOutputStream stream(&manager_, params_);
-
-  InitDispatcher(base::TimeDelta::FromMilliseconds(kTestCloseDelayMs));
-
-  EXPECT_CALL(manager(), MakeAudioOutputStream(_))
-      .WillOnce(Return(&stream));
-
-  EXPECT_CALL(stream, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream, Start(_))
-      .Times(1);
-  EXPECT_CALL(stream, SetVolume(_))
-      .Times(1);
-  EXPECT_CALL(stream, Stop())
-      .Times(1);
-  EXPECT_CALL(stream, Close())
-      .Times(1);
-
-  AudioOutputProxy* proxy1 = new AudioOutputProxy(mixer_);
-  AudioOutputProxy* proxy2 = new AudioOutputProxy(mixer_);
-  EXPECT_TRUE(proxy1->Open());
-  EXPECT_TRUE(proxy2->Open());
-
-  proxy1->Start(&callback_);
-  proxy1->Stop();
-
-  proxy1->Close();
-  proxy2->Close();
-  WaitForCloseTimer(kTestCloseDelayMs);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, TwoStreams_OnePlaying) {
   InitDispatcher(base::TimeDelta::FromSeconds(kTestBigCloseDelaySeconds));
   TwoStreams_OnePlaying(resampler_);
@@ -627,71 +549,6 @@ TEST_F(AudioOutputProxyTest, TwoStreams_BothPlaying) {
   TwoStreams_BothPlaying(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-// Two streams, both are playing. Still have to use single device.
-// Also verifies that every proxy stream gets its own pending_bytes.
-TEST_F(AudioOutputProxyTest, TwoStreams_BothPlaying_Mixer) {
-  MockAudioOutputStream stream(&manager_, params_);
-
-  InitDispatcher(base::TimeDelta::FromMilliseconds(kTestCloseDelayMs));
-
-  EXPECT_CALL(manager(), MakeAudioOutputStream(_))
-      .WillOnce(Return(&stream));
-
-  EXPECT_CALL(stream, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream, Start(_))
-      .Times(1);
-  EXPECT_CALL(stream, SetVolume(_))
-      .Times(1);
-  EXPECT_CALL(stream, Stop())
-      .Times(1);
-  EXPECT_CALL(stream, Close())
-      .Times(1);
-
-  AudioOutputProxy* proxy1 = new AudioOutputProxy(mixer_);
-  AudioOutputProxy* proxy2 = new AudioOutputProxy(mixer_);
-  EXPECT_TRUE(proxy1->Open());
-  EXPECT_TRUE(proxy2->Open());
-
-  proxy1->Start(&callback_);
-
-  // Mute the proxy. Resulting stream should still have correct length.
-  proxy1->SetVolume(0.0);
-
-  uint8 zeroes[4] = {0, 0, 0, 0};
-  uint8 buf1[4] = {0};
-  EXPECT_CALL(callback_,
-      OnMoreData(NotNull(), 4,
-                 AllOf(Field(&AudioBuffersState::pending_bytes, 0),
-                       Field(&AudioBuffersState::hardware_delay_bytes, 0))))
-      .WillOnce(DoAll(SetArrayArgument<0>(zeroes, zeroes + sizeof(zeroes)),
-                      Return(4)));
-  mixer_->OnMoreData(buf1, sizeof(buf1), AudioBuffersState(0, 0));
-  proxy2->Start(&callback_);
-  uint8 buf2[4] = {0};
-  EXPECT_CALL(callback_,
-      OnMoreData(NotNull(), 4,
-                 AllOf(Field(&AudioBuffersState::pending_bytes, 4),
-                       Field(&AudioBuffersState::hardware_delay_bytes, 0))))
-      .WillOnce(DoAll(SetArrayArgument<0>(zeroes, zeroes + sizeof(zeroes)),
-                      Return(4)));
-  EXPECT_CALL(callback_,
-      OnMoreData(NotNull(), 4,
-                 AllOf(Field(&AudioBuffersState::pending_bytes, 0),
-                       Field(&AudioBuffersState::hardware_delay_bytes, 0))))
-      .WillOnce(DoAll(SetArrayArgument<0>(zeroes, zeroes + sizeof(zeroes)),
-                      Return(4)));
-  mixer_->OnMoreData(buf2, sizeof(buf2), AudioBuffersState(4, 0));
-  proxy1->Stop();
-  proxy2->Stop();
-
-  proxy1->Close();
-  proxy2->Close();
-  WaitForCloseTimer(kTestCloseDelayMs);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, TwoStreams_BothPlaying) {
   InitDispatcher(base::TimeDelta::FromSeconds(kTestBigCloseDelaySeconds));
   TwoStreams_BothPlaying(resampler_);
@@ -701,12 +558,6 @@ TEST_F(AudioOutputProxyTest, OpenFailed) {
   OpenFailed(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-TEST_F(AudioOutputProxyTest, OpenFailed_Mixer) {
-  OpenFailed(mixer_);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, OpenFailed) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisableAudioFallback);
@@ -718,52 +569,6 @@ TEST_F(AudioOutputProxyTest, StartFailed) {
   StartFailed(dispatcher_impl_);
 }
 
-#if defined(ENABLE_AUDIO_MIXER)
-// Start() method failed.
-TEST_F(AudioOutputProxyTest, StartFailed_Mixer) {
-  MockAudioOutputStream stream(&manager_, params_);
-
-  EXPECT_CALL(manager(), MakeAudioOutputStream(_))
-      .WillOnce(Return(&stream));
-  EXPECT_CALL(stream, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream, Close())
-      .Times(1);
-  EXPECT_CALL(stream, Start(_))
-      .Times(1);
-  EXPECT_CALL(stream, SetVolume(_))
-      .Times(1);
-  EXPECT_CALL(stream, Stop())
-      .Times(1);
-
-  AudioOutputProxy* proxy1 = new AudioOutputProxy(mixer_);
-  AudioOutputProxy* proxy2 = new AudioOutputProxy(mixer_);
-  EXPECT_TRUE(proxy1->Open());
-  EXPECT_TRUE(proxy2->Open());
-  proxy1->Start(&callback_);
-  proxy1->Stop();
-  proxy1->Close();
-  WaitForCloseTimer(kTestCloseDelayMs);
-
-  // Verify expectation before continueing.
-  Mock::VerifyAndClear(&stream);
-
-  // |stream| is closed at this point. Start() should reopen it again.
-  EXPECT_CALL(manager(), MakeAudioOutputStream(_))
-      .WillOnce(Return(reinterpret_cast<AudioOutputStream*>(NULL)));
-
-  EXPECT_CALL(callback_, OnError(_, _))
-      .Times(1);
-
-  proxy2->Start(&callback_);
-
-  Mock::VerifyAndClear(&callback_);
-
-  proxy2->Close();
-  WaitForCloseTimer(kTestCloseDelayMs);
-}
-#endif
-
 TEST_F(AudioOutputResamplerTest, StartFailed) {
   StartFailed(resampler_);
 }
diff --git a/media/audio/audio_util.cc b/media/audio/audio_util.cc
index 4c446dd..7342801f 100644
--- a/media/audio/audio_util.cc
+++ b/media/audio/audio_util.cc
@@ -70,20 +70,6 @@ static void AdjustVolume(Format* buf_out,
   }
 }
 
-static const int kChannel_L = 0;
-static const int kChannel_R = 1;
-static const int kChannel_C = 2;
-
-template<class Fixed, int min_value, int max_value>
-static int AddSaturated(int val, int adder) {
-  Fixed sum = static_cast<Fixed>(val) + static_cast<Fixed>(adder);
-  if (sum > max_value)
-    return max_value;
-  if (sum < min_value)
-    return min_value;
-  return static_cast<int>(sum);
-}
-
 // AdjustVolume() does an in place audio sample change.
 bool AdjustVolume(void* buf,
                   size_t buflen,
@@ -122,72 +108,6 @@ bool AdjustVolume(void* buf,
   return false;
 }
 
-// TODO(enal): use template specialization and size-specific intrinsics.
-//             Call is on the time-critical path, and by using SSE/AVX
-//             instructions we can speed things up by ~4-8x, more for the case
-//             when we have to adjust volume as well.
-template<class Format, class Fixed, int min_value, int max_value, int bias>
-static void MixStreams(Format* dst, Format* src, int count, float volume) {
-  if (volume == 0.0f)
-    return;
-  if (volume == 1.0f) {
-    // Most common case -- no need to adjust volume.
-    for (int i = 0; i < count; ++i) {
-      Fixed value = AddSaturated<Fixed, min_value, max_value>(dst[i] - bias,
-                                                              src[i] - bias);
-      dst[i] = static_cast<Format>(value + bias);
-    }
-  } else {
-    // General case -- have to adjust volume before mixing.
-    const int fixed_volume = static_cast<int>(volume * 65536);
-    for (int i = 0; i < count; ++i) {
-      Fixed adjusted_src = ScaleChannel<Fixed>(src[i] - bias, fixed_volume);
-      Fixed value = AddSaturated<Fixed, min_value, max_value>(dst[i] - bias,
-                                                              adjusted_src);
-      dst[i] = static_cast<Format>(value + bias);
-    }
-  }
-}
-
-void MixStreams(void* dst,
-                void* src,
-                size_t buflen,
-                int bytes_per_sample,
-                float volume) {
-  DCHECK(dst);
-  DCHECK(src);
-  DCHECK_GE(volume, 0.0f);
-  DCHECK_LE(volume, 1.0f);
-  switch (bytes_per_sample) {
-    case 1:
-      MixStreams<uint8, int32, kint8min, kint8max, 128>(
-          static_cast<uint8*>(dst),
-          static_cast<uint8*>(src),
-          buflen,
-          volume);
-      break;
-    case 2:
-      DCHECK_EQ(0u, buflen % 2);
-      MixStreams<int16, int32, kint16min, kint16max, 0>(
-          static_cast<int16*>(dst),
-          static_cast<int16*>(src),
-          buflen / 2,
-          volume);
-      break;
-    case 4:
-      DCHECK_EQ(0u, buflen % 4);
-      MixStreams<int32, int64, kint32min, kint32max, 0>(
-          static_cast<int32*>(dst),
-          static_cast<int32*>(src),
-          buflen / 4,
-          volume);
-      break;
-    default:
-      NOTREACHED() << "Illegal bytes per sample";
-      break;
-  }
-}
-
 int GetAudioHardwareSampleRate() {
 #if defined(OS_MACOSX)
   // Hardware sample-rate on the Mac can be configured, so we must query.
diff --git a/media/audio/audio_util.h b/media/audio/audio_util.h
index 18cda41..6067b21 100644
--- a/media/audio/audio_util.h
+++ b/media/audio/audio_util.h
@@ -39,15 +39,6 @@ MEDIA_EXPORT bool AdjustVolume(void* buf,
                                int bytes_per_sample,
                                float volume);
 
-// MixStreams() mixes 2 audio streams with same sample rate and number of
-// samples, adjusting volume on one of them.
-// Dst += Src * volume.
-MEDIA_EXPORT void MixStreams(void* dst,
-                             void* src,
-                             size_t buflen,
-                             int bytes_per_sample,
-                             float volume);
-
 // Returns the default audio output hardware sample-rate.
 MEDIA_EXPORT int GetAudioHardwareSampleRate();
 
diff --git a/media/audio/audio_util_unittest.cc b/media/audio/audio_util_unittest.cc
index 2643b99..679243c 100644
--- a/media/audio/audio_util_unittest.cc
+++ b/media/audio/audio_util_unittest.cc
@@ -79,86 +79,4 @@ TEST(AudioUtilTest, AdjustVolume_s32) {
   EXPECT_EQ(0, expected_test);
 }
 
-TEST(AudioUtilTest, MixStreams_u8_QuarterVolume) {
-  // Test MixStreams() on 8 bit samples.
-  uint8 dst_u8[kNumberOfSamples] = { 14, 0x44, 0x80, 0xff };
-  uint8 src_u8[kNumberOfSamples] = { 4, 0x40, 0x80, 0xff };
-  uint8 expected_u8[kNumberOfSamples] = { 0,  /* saturation */
-                                          (0x44 - 128) + (0x40 - 128) / 4 + 128,
-                                          (0x80 - 128) + (0x80 - 128) / 4 + 128,
-                                          0xff /* saturation */ };
-  media::MixStreams(dst_u8, src_u8, sizeof(dst_u8), sizeof(src_u8[0]), 0.25f);
-  int expected_test = memcmp(dst_u8, expected_u8, sizeof(expected_u8));
-  EXPECT_EQ(0, expected_test);
-}
-
-TEST(AudioUtilTest, MixStreams_u8_FullVolume) {
-  // Test MixStreams() on 8 bit samples.
-  uint8 dst_u8[kNumberOfSamples] = { 44, 0x44, 0x80, 0xff };
-  uint8 src_u8[kNumberOfSamples] = { 4, 0x40, 0x80, 0xff };
-  uint8 expected_u8[kNumberOfSamples] = { 0,  /* saturation */
-                                          (0x44 - 128) + (0x40 - 128) + 128,
-                                          (0x80 - 128) + (0x80 - 128) + 128,
-                                          0xff /* saturation */ };
-  media::MixStreams(dst_u8, src_u8, sizeof(dst_u8), sizeof(src_u8[0]), 1.0f);
-  int expected_test = memcmp(dst_u8, expected_u8, sizeof(expected_u8));
-  EXPECT_EQ(0, expected_test);
-}
-
-TEST(AudioUtilTest, MixStreams_s16_QuarterVolume) {
-  // Test MixStreams() on 16 bit samples.
-  int16 dst_s16[kNumberOfSamples] = { -4, 0x40, -32760, 32760 };
-  int16 src_s16[kNumberOfSamples] = { -4, 0x40, -123, 123 };
-  int16 expected_s16[kNumberOfSamples] = { -5, 0x50, -32768, 32767 };
-  media::MixStreams(dst_s16,
-                    src_s16,
-                    sizeof(dst_s16),
-                    sizeof(src_s16[0]),
-                    0.25f);
-  int expected_test = memcmp(dst_s16, expected_s16, sizeof(expected_s16));
-  EXPECT_EQ(0, expected_test);
-}
-
-TEST(AudioUtilTest, MixStreams_s16_FullVolume) {
-  // Test MixStreams() on 16 bit samples.
-  int16 dst_s16[kNumberOfSamples] = { -4, 0x40, -32760, 32760 };
-  int16 src_s16[kNumberOfSamples] = { -4, 0x40, -123, 123 };
-  int16 expected_s16[kNumberOfSamples] = { -8, 0x80, -32768, 32767 };
-  media::MixStreams(dst_s16,
-                    src_s16,
-                    sizeof(dst_s16),
-                    sizeof(src_s16[0]),
-                    1.0f);
-  int expected_test = memcmp(dst_s16, expected_s16, sizeof(expected_s16));
-  EXPECT_EQ(0, expected_test);
-}
-
-TEST(AudioUtilTest, MixStreams_s32_QuarterVolume) {
-  // Test MixStreams() on 32 bit samples.
-  int32 dst_s32[kNumberOfSamples] = { -4, 0x40, -32768, 2147483640 };
-  int32 src_s32[kNumberOfSamples] = { -4, 0x40, -32768, 123 };
-  int32 expected_s32[kNumberOfSamples] = { -5, 0x50, -40960, 2147483647 };
-  media::MixStreams(dst_s32,
-                    src_s32,
-                    sizeof(dst_s32),
-                    sizeof(src_s32[0]),
-                    0.25f);
-  int expected_test = memcmp(dst_s32, expected_s32, sizeof(expected_s32));
-  EXPECT_EQ(0, expected_test);
-}
-
-TEST(AudioUtilTest, MixStreams_s32_FullVolume) {
-  // Test MixStreams() on 32 bit samples.
-  int32 dst_s32[kNumberOfSamples] = { -4, 0x40, -32768, 2147483640 };
-  int32 src_s32[kNumberOfSamples] = { -4, 0x40, -32768, 123 };
-  int32 expected_s32[kNumberOfSamples] = { -8, 0x80, -65536, 2147483647 };
-  media::MixStreams(dst_s32,
-                    src_s32,
-                    sizeof(dst_s32),
-                    sizeof(src_s32[0]),
-                    1.0);
-  int expected_test = memcmp(dst_s32, expected_s32, sizeof(expected_s32));
-  EXPECT_EQ(0, expected_test);
-}
-
 }  // namespace media
diff --git a/media/media.gyp b/media/media.gyp
index cc8be41..e27e956 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -67,10 +67,6 @@
         'audio/audio_input_device.h',
         'audio/audio_input_ipc.cc',
         'audio/audio_input_ipc.h',
-        # TODO(dalecurtis): Temporarily disabled while switching pipeline to use
-        # float, http://crbug.com/114700
-        # 'audio/audio_output_mixer.cc',
-        # 'audio/audio_output_mixer.h',
         'audio/audio_input_stream_impl.cc',
         'audio/audio_input_stream_impl.h',
         'audio/audio_io.h',