Moved AudioUtil static functions to AudioManager interfaces

media/audio/mac/audio_manager_mac.cc

Index: media/audio/mac/audio_manager_mac.cc
diff --git a/media/audio/mac/audio_manager_mac.cc b/media/audio/mac/audio_manager_mac.cc
index 4030a23a60bcdbc0d5585f405e44efed055428d0..a329278564abe42c7bd05ffcff5d3cbe1957c428 100644
--- a/media/audio/mac/audio_manager_mac.cc
+++ b/media/audio/mac/audio_manager_mac.cc
@@ -12,7 +12,7 @@
 #include "base/mac/mac_logging.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/sys_string_conversions.h"
-#include "media/audio/audio_util.h"
+#include "media/audio/audio_parameters.h"
 #include "media/audio/mac/audio_input_mac.h"
 #include "media/audio/mac/audio_low_latency_input_mac.h"
 #include "media/audio/mac/audio_low_latency_output_mac.h"
@@ -20,6 +20,7 @@
 #include "media/audio/mac/audio_synchronized_mac.h"
 #include "media/audio/mac/audio_unified_mac.h"
 #include "media/base/bind_to_loop.h"
+#include "media/base/channel_layout.h"
 #include "media/base/limits.h"
 #include "media/base/media_switches.h"
 
@@ -28,6 +29,9 @@ namespace media {
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
+// Default buffer size in samples for low-latency input and output streams.
+static const int kDefaultLowLatencyBufferSize = 128;
+
 static bool HasAudioHardware(AudioObjectPropertySelector selector) {
   AudioDeviceID output_device_id = kAudioObjectUnknown;
   const AudioObjectPropertyAddress property_address = {
@@ -273,6 +277,22 @@ void AudioManagerMac::GetAudioInputDeviceNames(
   }
 }
 
+AudioParameters AudioManagerMac::GetDefaultOutputStreamParameters() {
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
+      AUAudioOutputStream::HardwareSampleRate(), 16,
+      kDefaultLowLatencyBufferSize);
+}
+
+AudioParameters AudioManagerMac::GetDefaultInputStreamParameters(
+    const std::string& device_id) {
+  // TODO(xians): query the native channel layout for the specific device.
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
+      AUAudioInputStream::HardwareSampleRate(), 16,
+      kDefaultLowLatencyBufferSize);
+}
+
 AudioOutputStream* AudioManagerMac::MakeLinearOutputStream(
     const AudioParameters& params) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
@@ -329,10 +349,11 @@ AudioParameters AudioManagerMac::GetPreferredLowLatencyOutputStreamParameters(
     // back-ends used with kEnableWebAudioInput, we hard-code to stereo.
     // Specifically, this is a limitation of AudioSynchronizedStream which
     // can be removed as part of the work to consolidate these back-ends.
+    AudioParameters default_params = GetDefaultOutputStreamParameters();
     return AudioParameters(
         AudioParameters::AUDIO_PCM_LOW_LATENCY,
         CHANNEL_LAYOUT_STEREO, input_params.input_channels(),
-        GetAudioHardwareSampleRate(), 16, GetAudioHardwareBufferSize());
+        default_params.sample_rate(), 16, default_params.frames_per_buffer());
   }
 
   return AudioManagerBase::GetPreferredLowLatencyOutputStreamParameters(