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

media/audio/alsa/audio_manager_alsa.cc

Index: media/audio/alsa/audio_manager_alsa.cc
diff --git a/media/audio/alsa/audio_manager_alsa.cc b/media/audio/alsa/audio_manager_alsa.cc
index beb60bad88b02af515dd1075fb54a43edd226cb6..4bfd2452982115913a4f24fc67eb0c03b6986bfa 100644
--- a/media/audio/alsa/audio_manager_alsa.cc
+++ b/media/audio/alsa/audio_manager_alsa.cc
@@ -107,13 +107,24 @@ void AudioManagerAlsa::GetAudioOutputDeviceNames(
   GetAlsaAudioDevices(kStreamPlayback, device_names);
 }
 
-AudioParameters AudioManagerAlsa::GetInputStreamParameters(
-    const std::string& device_id) {
+AudioParameters AudioManagerAlsa::GetPreferredInputStreamParameters(
+    const std::string& input_device_id,
+    const AudioParameters& input_params) {
   static const int kDefaultInputBufferSize = 1024;
+  ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
+  int sample_rate = kDefaultSampleRate;
+  int buffer_size = kDefaultInputBufferSize;
+  int bits_per_sample = 16;
+  if (input_params.IsValid()) {
+    sample_rate = input_params.sample_rate();
+    bits_per_sample = input_params.bits_per_sample();
+    channel_layout = input_params.channel_layout();
+    buffer_size = input_params.frames_per_buffer();
+  }
 
   return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
-      kDefaultSampleRate, 16, kDefaultInputBufferSize);
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
+      sample_rate, bits_per_sample, buffer_size);
 }
 
 void AudioManagerAlsa::GetAlsaAudioDevices(