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

media/audio/audio_manager_base.cc

Index: media/audio/audio_manager_base.cc
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index 3b36b106fa681659dc78b6e894a1965a7d93cae4..6d328af274cfffe8052b83be93f7f9d232de6281 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -9,6 +9,7 @@
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "build/build_config.h"
+#include "media/audio/audio_input_proxy.h"
 #include "media/audio/audio_output_dispatcher_impl.h"
 #include "media/audio/audio_output_proxy.h"
 #include "media/audio/audio_output_resampler.h"
@@ -203,9 +204,14 @@ AudioInputStream* AudioManagerBase::MakeAudioInputStream(
     case AudioParameters::AUDIO_PCM_LINEAR:
       stream = MakeLinearInputStream(params, device_id);
       break;
-    case AudioParameters::AUDIO_PCM_LOW_LATENCY:
-      stream = MakeLowLatencyInputStream(params, device_id);
+    case AudioParameters::AUDIO_PCM_LOW_LATENCY: {
+      const AudioParameters hardware_params =
+          GetSupportedInputHardwareParameters(device_id, params);
+      input_proxies_.push_back(
+          new AudioInputProxy(this, params, hardware_params, device_id));
+      stream = static_cast<AudioInputStream*>(input_proxies_.back());
       break;
+    }
     case AudioParameters::AUDIO_FAKE:
       stream = FakeAudioInputStream::MakeFakeStream(this, params);
       break;
@@ -334,10 +340,14 @@ void AudioManagerBase::Shutdown() {
 
 void AudioManagerBase::ShutdownOnAudioThread() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(input_proxies_.empty());
   while (!output_dispatchers_.empty()) {
     output_dispatchers_.back()->dispatcher->Shutdown();
     output_dispatchers_.pop_back();
   }
+
+  while (!input_proxies_.empty())
+    input_proxies_.pop_back();
 }
 
 void AudioManagerBase::AddOutputDeviceChangeListener(
@@ -371,8 +381,8 @@ AudioParameters AudioManagerBase::GetOutputStreamParameters(
 
 AudioParameters AudioManagerBase::GetInputStreamParameters(
     const std::string& device_id) {
-  NOTREACHED();
-  return AudioParameters();
+  return GetPreferredInputStreamParameters(device_id,
+                                           AudioParameters());
 }
 
 std::string AudioManagerBase::GetAssociatedOutputDeviceID(
@@ -400,4 +410,40 @@ scoped_ptr<AudioLog> AudioManagerBase::CreateAudioLog(
   return audio_log_factory_->CreateAudioLog(component);
 }
 
+AudioParameters AudioManagerBase::GetSupportedInputHardwareParameters(
+    const std::string& device_id, const AudioParameters& preferred_params) {
+  // Delete all the idle input proxy streams.
+  for (AudioInputProxies::iterator iter = input_proxies_.begin();
+       iter != input_proxies_.end();) {
+    if ((*iter)->is_idle())
+      input_proxies_.erase(iter++);
+    else
+      ++iter;
+  }
+
+//#if defined(OS_MACOSX)
+  // Find out if the existing streams using different format to open
+  // the device, if there is any, we should force all the existing streams and
+  // the new stream to use the native hardware parameters.
+  AudioParameters use_native_params;
+  for (AudioInputProxies::iterator iter = input_proxies_.begin();
+       iter != input_proxies_.end(); ++iter) {
+    if ((*iter)->device_id() == device_id &&
+        (*iter)->input_parameters() != preferred_params) {
+      if (!use_native_params.IsValid()) {
+        use_native_params = GetInputStreamParameters(device_id);
+        DCHECK(use_native_params.IsValid());
+      }
+
+      (*iter)->MaybeRestartStream(use_native_params);
+    }
+  }
+
+  if (use_native_params.IsValid())
+    return use_native_params;
+//#endif
+
+  return preferred_params;
+}
+
 }  // namespace media