fallback to null sink in WebAudioSourceProvider::Initialize() + UMA stats for device status

media/audio/audio_output_device.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/audio_output_device.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <cmath>
@@ skipping 307 matching lines @@
   DCHECK_EQ(state_, AUTHORIZING);
 
   // It may happen that a second authorization is received as a result to a
   // call to Start() after Stop(). If the status for the second authorization
   // differs from the first, it will not be reflected in |device_status_|
   // to avoid a race.
   // This scenario is unlikely. If it occurs, the new value will be
   // different from OUTPUT_DEVICE_STATUS_OK, so the AudioOutputDevice
   // will enter the IPC_CLOSED state anyway, which is the safe thing to do.
   // This is preferable to holding a lock.
-  if (!did_receive_auth_.IsSignaled())
+  if (!did_receive_auth_.IsSignaled()) {
     device_status_ = device_status;
+    UMA_HISTOGRAM_ENUMERATION("Media.Audio.Render.OutputDeviceStatus",
+                              device_status, OUTPUT_DEVICE_STATUS_MAX + 1);
+  }
 
   if (device_status == OUTPUT_DEVICE_STATUS_OK) {
     state_ = AUTHORIZED;
     if (!did_receive_auth_.IsSignaled()) {
       output_params_ = output_params;
 
       // It's possible to not have a matched device obtained via session id. It
       // means matching output device through |session_id_| failed and the
       // default device is used.
       DCHECK(AudioDeviceDescription::UseSessionIdToSelectDevice(session_id_,
@@ skipping 144 matching lines @@
   render_callback_->Render(delay, delay_timestamp, frames_skipped,
                            output_bus_.get());
 }
 
 bool AudioOutputDevice::AudioThreadCallback::
     CurrentThreadIsAudioDeviceThread() {
   return thread_checker_.CalledOnValidThread();
 }
 
 }  // namespace media