add audio-buffer-size command line flag support to the input audio for all the platforms

media/audio/fake_audio_manager.cc

Index: media/audio/fake_audio_manager.cc
diff --git a/media/audio/fake_audio_manager.cc b/media/audio/fake_audio_manager.cc
index e5d9bd4d8c8658df6056269dfd6b42017130e29a..99a8e8e2e7c0657c6ce0e6d5a742cbc70ead478b 100644
--- a/media/audio/fake_audio_manager.cc
+++ b/media/audio/fake_audio_manager.cc
@@ -8,8 +8,26 @@ namespace media {
 
 namespace {
 
-const int kDefaultInputBufferSize = 1024;
-const int kDefaultSampleRate = 48000;
+AudioParameters GetPreferredStreamParameters(
+    ChannelLayout default_channel_layout, int default_sample_rate,
+    int default_buffer_size, const AudioParameters& input_params) {
+  ChannelLayout channel_layout = default_channel_layout;
+  int sample_rate = default_sample_rate;
+  int buffer_size = default_buffer_size;
+  int bits_per_sample = 16;
+  int input_channels = 0;
+  if (input_params.IsValid()) {
+    sample_rate = input_params.sample_rate();
+    bits_per_sample = input_params.bits_per_sample();
+    channel_layout = input_params.channel_layout();
+    input_channels = input_params.input_channels();
+    buffer_size = std::min(input_params.frames_per_buffer(), buffer_size);
+  }
+
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
+      sample_rate, bits_per_sample, buffer_size, AudioParameters::NO_EFFECTS);
+}
 
 }  // namespace
 
@@ -53,30 +71,22 @@ AudioParameters FakeAudioManager::GetPreferredOutputStreamParameters(
     const std::string& output_device_id,
     const AudioParameters& input_params) {
   static const int kDefaultOutputBufferSize = 2048;
-  static const int kDefaultSampleRate = 48000;
-  ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
-  int sample_rate = kDefaultSampleRate;
-  int buffer_size = kDefaultOutputBufferSize;
-  int bits_per_sample = 16;
-  int input_channels = 0;
-  if (input_params.IsValid()) {
-    sample_rate = input_params.sample_rate();
-    bits_per_sample = input_params.bits_per_sample();
-    channel_layout = input_params.channel_layout();
-    input_channels = input_params.input_channels();
-    buffer_size = std::min(input_params.frames_per_buffer(), buffer_size);
-  }
-
-  return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
-      sample_rate, bits_per_sample, buffer_size, AudioParameters::NO_EFFECTS);
+  static const int kDefaultOutputSampleRate = 48000;
+  return GetPreferredStreamParameters(CHANNEL_LAYOUT_STEREO,
+                                      kDefaultOutputSampleRate,
+                                      kDefaultOutputBufferSize,
+                                      input_params);
 }
 
-AudioParameters FakeAudioManager::GetInputStreamParameters(
-    const std::string& device_id) {
-  return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      kDefaultSampleRate, 16, kDefaultInputBufferSize);
+AudioParameters FakeAudioManager::GetPreferredInputStreamParameters(
+    const std::string& input_device_id,
+    const AudioParameters& input_params) {
+  static const int kDefaultInputBufferSize = 1024;
+  static const int kDefaultInputSampleRate = 48000;
+  return GetPreferredStreamParameters(CHANNEL_LAYOUT_STEREO,
+                                      kDefaultInputSampleRate,
+                                      kDefaultInputBufferSize,
+                                      input_params);
 }
 
 }  // namespace media