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

webrtc/modules/audio_device/ios/audio_device_ios.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 31 matching lines @@
 class AudioDeviceIOS : public AudioDeviceGeneric,
                        public AudioSessionObserver,
                        public VoiceProcessingAudioUnitObserver,
                        public rtc::MessageHandler {
  public:
   AudioDeviceIOS();
   ~AudioDeviceIOS();
 
   void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer) override;
 
-  int32_t Init() override;
+  InitStatus Init() override;
   int32_t Terminate() override;
   bool Initialized() const override { return initialized_; }
 
   int32_t InitPlayout() override;
   bool PlayoutIsInitialized() const override { return play_is_initialized_; }
 
   int32_t InitRecording() override;
   bool RecordingIsInitialized() const override { return rec_is_initialized_; }
 
   int32_t StartPlayout() override;
@@ skipping 229 matching lines @@
   // Audio interruption observer instance.
   RTCAudioSessionDelegateAdapter* audio_session_observer_;
 
   // Set to true if we've activated the audio session.
   bool has_configured_session_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_