Mac AVFoundation: Enumerate devices in device/audio thread. Take 2.

content/browser/renderer_host/media/media_stream_manager.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/browser/renderer_host/media/media_stream_manager.h"
 
 #include <list>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 32 matching lines @@
 
 #if defined(OS_WIN)
 #include "base/win/scoped_com_initializer.h"
 #endif
 
 namespace content {
 
 // Forward declaration of DeviceMonitorMac and its only useable method.
 class DeviceMonitorMac {
  public:
-  void StartMonitoring();
+  void StartMonitoring(
+    const scoped_refptr<base::SingleThreadTaskRunner>& device_task_runner);
 };
 
 namespace {
 // Creates a random label used to identify requests.
 std::string RandomLabel() {
   // An earlier PeerConnection spec,
   // http://dev.w3.org/2011/webrtc/editor/webrtc.html, specified the
   // MediaStream::label alphabet as containing 36 characters from
   // range: U+0021, U+0023 to U+0027, U+002A to U+002B, U+002D to U+002E,
   // U+0030 to U+0039, U+0041 to U+005A, U+005E to U+007E.
@@ skipping 766 matching lines @@
       BrowserThread::UI, FROM_HERE,
       base::Bind(&MediaStreamManager::StartMonitoringOnUIThread,
                  base::Unretained(this)));
 #endif
 }
 
 #if defined(OS_MACOSX)
 void MediaStreamManager::StartMonitoringOnUIThread() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   BrowserMainLoop* browser_main_loop = content::BrowserMainLoop::GetInstance();
-  if (browser_main_loop)
-    browser_main_loop->device_monitor_mac()->StartMonitoring();
+  if (browser_main_loop) {
+    browser_main_loop->device_monitor_mac()
+        ->StartMonitoring(audio_manager_->GetWorkerTaskRunner());
+  }
 }
 #endif
 
 void MediaStreamManager::StopMonitoring() {
   DCHECK_EQ(base::MessageLoop::current(), io_loop_);
   if (monitoring_started_) {
     base::SystemMonitor::Get()->RemoveDevicesChangedObserver(this);
     monitoring_started_ = false;
     ClearEnumerationCache(&audio_enumeration_cache_);
     ClearEnumerationCache(&video_enumeration_cache_);
@@ skipping 1078 matching lines @@
       if (it->device.type == MEDIA_DESKTOP_VIDEO_CAPTURE) {
         video_capture_manager_->SetDesktopCaptureWindowId(it->session_id,
                                                           window_id);
         break;
       }
     }
   }
 }
 
 }  // namespace content