Add performance tracing to AudioDevice inits.

webrtc/modules/audio_device/audio_device_impl.cc

Index: webrtc/modules/audio_device/audio_device_impl.cc
diff --git a/webrtc/modules/audio_device/audio_device_impl.cc b/webrtc/modules/audio_device/audio_device_impl.cc
index d881bcd40c9293358b6ac8f1b5a21c3e8cc78982..6576f5d8e92b8b50d8dd10d37017f7627b068e8f 100644
--- a/webrtc/modules/audio_device/audio_device_impl.cc
+++ b/webrtc/modules/audio_device/audio_device_impl.cc
@@ -9,6 +9,7 @@
  */
 
 #include "webrtc/base/refcount.h"
+#include "webrtc/base/trace_event.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 #include "webrtc/modules/audio_device/audio_device_config.h"
 #include "webrtc/modules/audio_device/audio_device_impl.h"
@@ -1454,6 +1455,7 @@ int32_t AudioDeviceModuleImpl::InitPlayout()
 
 int32_t AudioDeviceModuleImpl::InitRecording()
 {
+    TRACE_EVENT0("webrtc", "AudioDeviceModuleImpl::InitRecording");
     CHECK_INITIALIZED();
     _audioDeviceBuffer.InitRecording();
     return (_ptrAudioDevice->InitRecording());
@@ -1515,6 +1517,7 @@ bool AudioDeviceModuleImpl::Playing() const
 
 int32_t AudioDeviceModuleImpl::StartRecording()
 {
+    TRACE_EVENT0("webrtc", "AudioDeviceModuleImpl::StartRecording");
     CHECK_INITIALIZED();
     return (_ptrAudioDevice->StartRecording());
 }