Pass task runners to AudioManager constructor.

media/audio/linux/audio_manager_linux.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 "base/command_line.h"
 #include "base/metrics/histogram.h"
+#include "media/base/media_switches.h"
+
 #if defined(USE_ALSA)
 #include "media/audio/alsa/audio_manager_alsa.h"
 #else
 #include "media/audio/fake_audio_manager.h"
 #endif
 #if defined(USE_CRAS)
 #include "media/audio/cras/audio_manager_cras.h"
 #endif
 #if defined(USE_PULSEAUDIO)
 #include "media/audio/pulse/audio_manager_pulse.h"
 #endif
-#include "media/base/media_switches.h"
 
 namespace media {
 
 enum LinuxAudioIO {
   kPulse,
   kAlsa,
   kCras,
   kAudioIOMax = kCras  // Must always be equal to largest logged entry.
 };
 
-AudioManager* CreateAudioManager(AudioLogFactory* audio_log_factory) {
+ScopedAudioManagerPtr CreateAudioManager(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
+    AudioLogFactory* audio_log_factory) {
 #if defined(USE_CRAS)
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseCras)) {
     UMA_HISTOGRAM_ENUMERATION("Media.LinuxAudioIO", kCras, kAudioIOMax + 1);
-    return new AudioManagerCras(audio_log_factory);
+    return ScopedAudioManagerPtr(
+        new AudioManagerCras(std::move(task_runner),
+                             std::move(worker_task_runner), audio_log_factory));
   }
 #endif
 
 #if defined(USE_PULSEAUDIO)
-  AudioManager* manager = AudioManagerPulse::Create(audio_log_factory);
-  if (manager) {
+  // Do not move task runners when creating AudioManagerPulse.
+  // If the creation fails, we need to use the task runners to create other
+  // AudioManager implementations.
+  std::unique_ptr<AudioManagerPulse, AudioManagerDeleter> manager(
+      new AudioManagerPulse(task_runner, worker_task_runner,
+                            audio_log_factory));
+  if (manager->Init()) {
     UMA_HISTOGRAM_ENUMERATION("Media.LinuxAudioIO", kPulse, kAudioIOMax + 1);
-    return manager;
+    return std::move(manager);
+  } else {

[tommi (sloooow) - chröme, 2016/04/13 07:31:51]

nit: no need for this scope since there's an early return above.  Since you
don't want to use the |manager| variable in the following lines, you could also
scope it:

  {
    // Do not move task runners when creating AudioManagerPulse.
    // If the creation fails, we need to use the task runners to create other
    // AudioManager implementations.
    std::unique_ptr<AudioManagerPulse, AudioManagerDeleter> manager(
        new AudioManagerPulse(task_runner, worker_task_runner,
                              audio_log_factory));
    if (manager->Init() {
      UMA_HISTOGRAM_ENUMERATION("Media.LinuxAudioIO", kPulse, kAudioIOMax + 1);
      return manager;
    }
  }

  DVLOG(1) << "PulseAudio is not available on the OS";
  ...

[alokp, 2016/04/17 16:55:19]

Done.

+    DVLOG(1) << "PulseAudio is not available on the OS";
+    manager.reset();
   }
 #endif
 
 #if defined(USE_ALSA)
   UMA_HISTOGRAM_ENUMERATION("Media.LinuxAudioIO", kAlsa, kAudioIOMax + 1);
-  return new AudioManagerAlsa(audio_log_factory);
+  return ScopedAudioManagerPtr(
+      new AudioManagerAlsa(std::move(task_runner),
+                           std::move(worker_task_runner), audio_log_factory));
 #else
-  return new FakeAudioManager(audio_log_factory);
+  return ScopedAudioManagerPtr(
+      new FakeAudioManager(std::move(task_runner),
+                           std::move(worker_task_runner), audio_log_factory));
 #endif
 }
 
 }  // namespace media