Change GetVolume() to be asynchronous when being called by pulse thread

content/renderer/media/webrtc_audio_device_impl.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 "content/renderer/media/webrtc_audio_device_impl.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/win/windows_version.h"
@@ skipping 126 matching lines @@
                                         int audio_delay_milliseconds,
                                         double volume) {
   DCHECK_LE(number_of_frames, input_buffer_size());
 #if defined(OS_WIN) || defined(OS_MACOSX)
   DCHECK_LE(volume, 1.0);
 #elif defined(OS_LINUX) || defined(OS_OPENBSD)
   // We have a special situation on Linux where the microphone volume can be
   // "higher than maximum". The input volume slider in the sound preference
   // allows the user to set a scaling that is higher than 100%. It means that
   // even if the reported maximum levels is N, the actual microphone level can
-  // go up to 1.5*N and that corresponds to a normalized |volume| of 1.5.
-  DCHECK_LE(volume, 1.5);
+  // go up to 1.5x*N and that corresponds to a normalized |volume| of 1.5x.
+  DCHECK_LE(volume, 1.6);
 #endif
 
   int output_delay_ms = 0;
   {
     base::AutoLock auto_lock(lock_);
     // Store the reported audio delay locally.
     input_delay_ms_ = audio_delay_milliseconds;
     output_delay_ms = output_delay_ms_;
   }
 
@@ skipping 690 matching lines @@
   NOTIMPLEMENTED();
   return -1;
 }
 
 int32_t WebRtcAudioDeviceImpl::GetLoudspeakerStatus(bool* enabled) const {
   NOTIMPLEMENTED();
   return -1;
 }
 
 }  // namespace content