UMA log for audio_device Init and Start(Playout|Recording). Make Init return a more specific error …

webrtc/modules/audio_device/mac/audio_device_mac.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 50 matching lines @@
 class AudioDeviceMac : public AudioDeviceGeneric {
  public:
   AudioDeviceMac(const int32_t id);
   ~AudioDeviceMac();
 
   // Retrieve the currently utilized audio layer
   virtual int32_t ActiveAudioLayer(
       AudioDeviceModule::AudioLayer& audioLayer) const;
 
   // Main initializaton and termination
-  virtual int32_t Init();
+  virtual InitStatus Init();
   virtual int32_t Terminate();
   virtual bool Initialized() const;
 
   // Device enumeration
   virtual int16_t PlayoutDevices();
   virtual int16_t RecordingDevices();
   virtual int32_t PlayoutDeviceName(uint16_t index,
                                     char name[kAdmMaxDeviceNameSize],
                                     char guid[kAdmMaxGuidSize]);
   virtual int32_t RecordingDeviceName(uint16_t index,
@@ skipping 293 matching lines @@
   // Typing detection
   // 0x5c is key "9", after that comes function keys.
   bool prev_key_state_[0x5d];
 
   int get_mic_volume_counter_ms_;
 };
 
 }  // namespace webrtc
 
 #endif  // MODULES_AUDIO_DEVICE_MAIN_SOURCE_MAC_AUDIO_DEVICE_MAC_H_