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

media/audio/pulse/audio_manager_pulse.cc

Index: media/audio/pulse/audio_manager_pulse.cc
diff --git a/media/audio/pulse/audio_manager_pulse.cc b/media/audio/pulse/audio_manager_pulse.cc
index 412f2a421b0f46dd6375bf7ab3d7d17d051484fe..2cf1d9815a3d1d601dfcc2f7628daafd939022dd 100644
--- a/media/audio/pulse/audio_manager_pulse.cc
+++ b/media/audio/pulse/audio_manager_pulse.cc
@@ -35,9 +35,11 @@ using pulse::WaitForOperationCompletion;
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
-// Define bounds for the output buffer size.
+// Minimum bound for the output buffer size.
 static const int kMinimumOutputBufferSize = 512;
-static const int kMaximumOutputBufferSize = 8192;
+
+// Maximum bound for the input and output buffer size
+static const int kMaximumBufferSize = 8192;
 
 // Default input buffer size.
 static const int kDefaultInputBufferSize = 1024;
@@ -126,16 +128,31 @@ void AudioManagerPulse::GetAudioOutputDeviceNames(
   GetAudioDeviceNames(false, device_names);
 }
 
-AudioParameters AudioManagerPulse::GetInputStreamParameters(
-    const std::string& device_id) {
+AudioParameters AudioManagerPulse::GetPreferredInputStreamParameters(
+    const std::string& input_device_id,
+    const AudioParameters& input_params) {
+  // TODO(xians): add support for querying native channel layout for pulse.
+  ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
+  int buffer_size = kDefaultInputBufferSize;
+  int bits_per_sample = 16;
+  int input_channels = 0;
+  int sample_rate = GetNativeSampleRate();
+  if (input_params.IsValid()) {
+    bits_per_sample = input_params.bits_per_sample();
+    channel_layout = input_params.channel_layout();
+    input_channels = input_params.input_channels();
+    buffer_size = std::min(kMaximumBufferSize,
+                           input_params.frames_per_buffer());
+    sample_rate = input_params.sample_rate();
+  }
+
   int user_buffer_size = GetUserBufferSize();
-  int buffer_size = user_buffer_size ?
-      user_buffer_size : kDefaultInputBufferSize;
+  if (user_buffer_size)
+    buffer_size = user_buffer_size;
 
-  // TODO(xians): add support for querying native channel layout for pulse.
   return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      GetNativeSampleRate(), 16, buffer_size);
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
+      sample_rate, bits_per_sample, buffer_size, AudioParameters::NO_EFFECTS);
 }
 
 AudioOutputStream* AudioManagerPulse::MakeLinearOutputStream(
@@ -175,13 +192,13 @@ AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
   int buffer_size = kMinimumOutputBufferSize;
   int bits_per_sample = 16;
   int input_channels = 0;
-  int sample_rate;
+  int sample_rate = 0;
   if (input_params.IsValid()) {
     bits_per_sample = input_params.bits_per_sample();
     channel_layout = input_params.channel_layout();
     input_channels = input_params.input_channels();
     buffer_size =
-        std::min(kMaximumOutputBufferSize,
+        std::min(kMaximumBufferSize,
                  std::max(buffer_size, input_params.frames_per_buffer()));
     sample_rate = input_params.sample_rate();
   } else {