Avoid shutdown crash if audio thread is hung.

media/audio/audio_manager_base.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_manager_base.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 80 matching lines @@
       max_num_input_streams_(kDefaultMaxInputStreams),
       num_output_streams_(0),
       // TODO(dalecurtis): Switch this to an base::ObserverListThreadSafe, so we
       // don't block the UI thread when swapping devices.
       output_listeners_(
           base::ObserverList<AudioDeviceListener>::NOTIFY_EXISTING_ONLY),
       audio_log_factory_(audio_log_factory) {}
 
 AudioManagerBase::~AudioManagerBase() {
   // All the output streams should have been deleted.
-  CHECK_EQ(0, num_output_streams_);
+  DCHECK_EQ(0, num_output_streams_);

[alokp, 2017/06/13 23:35:51]

Changing CHECKs in the constructor to DCHECKs since we are intentionally leaking
these streams if audio thread is hung.

[DaleCurtis, 2017/06/13 23:43:15]

I think a better option would be to skip AM::Shutdown(), ~AM and ~AudioSystem if
the audio thread is hung and mark it as a "TODO(olka, grunell): Will be fixed
when audio is its own process."

[alokp, 2017/06/14 17:34:35]

Good idea. Done.

   // All the input streams should have been deleted.
-  CHECK(input_streams_.empty());
+  DCHECK(input_streams_.empty());
 }
 
 base::string16 AudioManagerBase::GetAudioInputDeviceModel() {
   return base::string16();
 }
 
 void AudioManagerBase::GetAudioInputDeviceDescriptions(
     AudioDeviceDescriptions* device_descriptions) {
   CHECK(GetTaskRunner()->BelongsToCurrentThread());
   AudioDeviceNames device_names;
@@ skipping 369 matching lines @@
   return base::MakeUnique<AudioDebugRecordingManager>(std::move(task_runner));
 }
 
 void AudioManagerBase::SetMaxStreamCountForTesting(int max_input,
                                                    int max_output) {
   max_num_output_streams_ = max_output;
   max_num_input_streams_ = max_input;
 }
 
 }  // namespace media