Mac AVFoundation/QTKit: delay DeviceMonitorMac startup to first GetUserMedia.

content/browser/renderer_host/media/media_stream_manager.h

 // 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.
 
 // MediaStreamManager is used to open/enumerate media capture devices (video
 // supported now). Call flow:
 // 1. GenerateStream is called when a render process wants to use a capture
 //    device.
 // 2. MediaStreamManager will ask MediaStreamUIController for permission to
 //    use devices and for which device to use.
@@ skipping 289 matching lines @@
   // list of currently available devices.
   void StopRemovedDevices(const StreamDeviceInfoArray& old_devices,
                           const StreamDeviceInfoArray& new_devices);
   // Helper method used by StopRemovedDevices to stop the use of a certain
   // device.
   void StopRemovedDevice(const MediaStreamDevice& device);
 
   // Helpers to start and stop monitoring devices.
   void StartMonitoring();
   void StopMonitoring();
+#if defined(OS_MACOSX)
+  void StartMonitoringOnUIThread();
+#endif
 
   // Finds the requested device id from constraints. The requested device type
   // must be MEDIA_DEVICE_AUDIO_CAPTURE or MEDIA_DEVICE_VIDEO_CAPTURE.
   bool GetRequestedDeviceCaptureId(const DeviceRequest* request,
                                    MediaStreamType type,
                                    std::string* device_id) const;
 
   void TranslateDeviceIdToSourceId(DeviceRequest* request,
                                    MediaStreamDevice* device);
 
@@ skipping 43 matching lines @@
 
   bool use_fake_ui_;
   scoped_ptr<FakeMediaStreamUIProxy> fake_ui_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_