Revert of Revert of Remove the last piece of deprecated synchronous IO code.

media/base/channel_mixer_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.
 
 // MSVC++ requires this to be set before any other includes to get M_SQRT1_2.
 #define _USE_MATH_DEFINES
 
 #include <cmath>
 
 #include "base/strings/stringprintf.h"
@@ skipping 89 matching lines @@
 // output channels have the same value.
 TEST_P(ChannelMixerTest, Mixing) {
   ChannelLayout input_layout = GetParam().input_layout;
   int input_channels = GetParam().input_channels;
   scoped_ptr<AudioBus> input_bus = AudioBus::Create(input_channels, kFrames);
   AudioParameters input_audio(AudioParameters::AUDIO_PCM_LINEAR,
                               input_layout,
                               input_layout == CHANNEL_LAYOUT_DISCRETE ?
                                   input_channels :
                                   ChannelLayoutToChannelCount(input_layout),
-                              0,
                               AudioParameters::kAudioCDSampleRate, 16,
                               kFrames,
                               AudioParameters::NO_EFFECTS);
 
   ChannelLayout output_layout = GetParam().output_layout;
   int output_channels = GetParam().output_channels;
   scoped_ptr<AudioBus> output_bus = AudioBus::Create(output_channels, kFrames);
   AudioParameters output_audio(AudioParameters::AUDIO_PCM_LINEAR,
                                output_layout,
                                output_layout == CHANNEL_LAYOUT_DISCRETE ?
-                                  output_channels :
-                                  ChannelLayoutToChannelCount(output_layout),
-                               0,
+                                   output_channels :
+                                   ChannelLayoutToChannelCount(output_layout),
                                AudioParameters::kAudioCDSampleRate, 16,
                                kFrames,
                                AudioParameters::NO_EFFECTS);
 
   const float* channel_values = GetParam().channel_values;
   ASSERT_EQ(input_bus->channels(), GetParam().num_channel_values);
 
   float expected_value = 0;
   float scale = GetParam().scale;
   for (int ch = 0; ch < input_bus->channels(); ++ch) {
@@ skipping 47 matching lines @@
                          kStereoToMonoValues, arraysize(kStereoToMonoValues)),
     ChannelMixerTestData(CHANNEL_LAYOUT_DISCRETE, 2,
                          CHANNEL_LAYOUT_DISCRETE, 5,
                          kStereoToMonoValues, arraysize(kStereoToMonoValues)),
     ChannelMixerTestData(CHANNEL_LAYOUT_DISCRETE, 5,
                          CHANNEL_LAYOUT_DISCRETE, 2,
                          kFiveDiscreteValues, arraysize(kFiveDiscreteValues))
 ));
 
 }  // namespace media