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

This is required to do some experiments with low buffer size for input audio.

BUG=363958
TEST=manual test with audio-buffer-size flag

Review URL: https://codereview.chromium.org/285233005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271673 0039d316-1c4b-4281-b951-d872f2087c98

media/audio/android/audio_manager_android.cc

@@ -123,13 +123,18 @@ AudioParameters AudioManagerAndroid::GetInputStreamParameters(
   int buffer_size = Java_AudioManagerAndroid_getMinInputFrameSize(
       env, GetNativeOutputSampleRate(),
       ChannelLayoutToChannelCount(channel_layout));
+  buffer_size = buffer_size <= 0 ? kDefaultInputBufferSize : buffer_size;
   int effects = AudioParameters::NO_EFFECTS;
   effects |= Java_AudioManagerAndroid_shouldUseAcousticEchoCanceler(env) ?
       AudioParameters::ECHO_CANCELLER : AudioParameters::NO_EFFECTS;
+
+  int user_buffer_size = GetUserBufferSize();
+  if (user_buffer_size)
+    buffer_size = user_buffer_size;
+
   AudioParameters params(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, 0,
-      GetNativeOutputSampleRate(), 16,
-      buffer_size <= 0 ? kDefaultInputBufferSize : buffer_size, effects);
+      GetNativeOutputSampleRate(), 16, buffer_size, effects);
   return params;
 }
 

media/audio/cras/audio_manager_cras.cc

@@ -41,6 +41,9 @@ static const int kDefaultSampleRate = 48000;
 static const int kMinimumOutputBufferSize = 512;
 static const int kMaximumOutputBufferSize = 8192;
 
+// Default input buffer size.
+static const int kDefaultInputBufferSize = 1024;
+
 bool AudioManagerCras::HasAudioOutputDevices() {
   return true;
 }
@@ -74,12 +77,15 @@ void AudioManagerCras::GetAudioOutputDeviceNames(
 
 AudioParameters AudioManagerCras::GetInputStreamParameters(
     const std::string& device_id) {
-  static const int kDefaultInputBufferSize = 1024;
+  int user_buffer_size = GetUserBufferSize();
+  int buffer_size = user_buffer_size ?
+      user_buffer_size : kDefaultInputBufferSize;
+
   // TODO(hshi): Fine-tune audio parameters based on |device_id|. The optimal
   // parameters for the loopback stream may differ from the default.
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      kDefaultSampleRate, 16, kDefaultInputBufferSize);
+      kDefaultSampleRate, 16, buffer_size);
 }
 
 AudioOutputStream* AudioManagerCras::MakeLinearOutputStream(

media/audio/openbsd/audio_manager_openbsd.cc

@@ -59,9 +59,13 @@ AudioParameters AudioManagerOpenBSD::GetInputStreamParameters(
     const std::string& device_id) {
   static const int kDefaultInputBufferSize = 1024;
 
+  int user_buffer_size = GetUserBufferSize();
+  int buffer_size = user_buffer_size ?
+      user_buffer_size : kDefaultInputBufferSize;
+
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      kDefaultSampleRate, 16, kDefaultInputBufferSize);
+      kDefaultSampleRate, 16, buffer_size);
 }
 
 AudioManagerOpenBSD::AudioManagerOpenBSD(AudioLogFactory* audio_log_factory)

media/audio/pulse/audio_manager_pulse.cc

@@ -39,6 +39,9 @@ static const int kMaxOutputStreams = 50;
 static const int kMinimumOutputBufferSize = 512;
 static const int kMaximumOutputBufferSize = 8192;
 
+// Default input buffer size.
+static const int kDefaultInputBufferSize = 1024;
+
 static const base::FilePath::CharType kPulseLib[] =
     FILE_PATH_LITERAL("libpulse.so.0");
 
@@ -125,12 +128,14 @@ void AudioManagerPulse::GetAudioOutputDeviceNames(
 
 AudioParameters AudioManagerPulse::GetInputStreamParameters(
     const std::string& device_id) {
-  static const int kDefaultInputBufferSize = 1024;
+  int user_buffer_size = GetUserBufferSize();
+  int buffer_size = user_buffer_size ?
+      user_buffer_size : kDefaultInputBufferSize;
 
   // TODO(xians): add support for querying native channel layout for pulse.
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      GetNativeSampleRate(), 16, kDefaultInputBufferSize);
+      GetNativeSampleRate(), 16, buffer_size);
 }
 
 AudioOutputStream* AudioManagerPulse::MakeLinearOutputStream(

media/audio/win/audio_manager_win.cc

@@ -301,13 +301,25 @@ void AudioManagerWin::GetAudioOutputDeviceNames(
 
 AudioParameters AudioManagerWin::GetInputStreamParameters(
     const std::string& device_id) {
+  AudioParameters parameters;
   if (!core_audio_supported()) {
-    return AudioParameters(
+    // Windows Wave implementation is being used.
+    parameters = AudioParameters(
         AudioParameters::AUDIO_PCM_LINEAR, CHANNEL_LAYOUT_STEREO, 0, 48000,
         16, kFallbackBufferSize, AudioParameters::NO_EFFECTS);
+  } else  {
+    parameters = WASAPIAudioInputStream::GetInputStreamParameters(device_id);
   }
 
-  return WASAPIAudioInputStream::GetInputStreamParameters(device_id);
+  int user_buffer_size = GetUserBufferSize();
+  if (user_buffer_size) {
+    parameters.Reset(parameters.format(), parameters.channel_layout(),
+                     parameters.channels(), parameters.input_channels(),
+                     parameters.sample_rate(), parameters.bits_per_sample(),
+                     user_buffer_size);
+  }
+
+  return parameters;
 }
 
 std::string AudioManagerWin::GetAssociatedOutputDeviceID(