VideoCaptureDeviceFactory: Change device enumeration to callback + QTKit enumerates in UI thread.

media/video/capture/win/video_capture_device_factory_win.cc

 // Copyright 2014 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/video/capture/win/video_capture_device_factory_win.h"
 
 #include <mfapi.h>
 #include <mferror.h>
 
 #include "base/command_line.h"
@@ skipping 369 matching lines @@
   // 8 in non-Metro mode.
   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
   use_media_foundation_ = (base::win::IsMetroProcess() &&
       !cmd_line->HasSwitch(switches::kForceDirectShowVideoCapture)) ||
      (base::win::GetVersion() >= base::win::VERSION_WIN7 &&
       cmd_line->HasSwitch(switches::kForceMediaFoundationVideoCapture));
 }
 
 
 scoped_ptr<VideoCaptureDevice> VideoCaptureDeviceFactoryWin::Create(
-    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
     const VideoCaptureDevice::Name& device_name) {
   DCHECK(thread_checker_.CalledOnValidThread());
   scoped_ptr<VideoCaptureDevice> device;
   if (device_name.capture_api_type() ==
       VideoCaptureDevice::Name::MEDIA_FOUNDATION) {
     DCHECK(PlatformSupportsMediaFoundation());
     device.reset(new VideoCaptureDeviceMFWin(device_name));
     DVLOG(1) << " MediaFoundation Device: " << device_name.name();
     ScopedComPtr<IMFMediaSource> source;
     if (!CreateVideoCaptureDeviceMediaFoundation(device_name.id().c_str(),
@@ skipping 27 matching lines @@
     const VideoCaptureDevice::Name& device,
     VideoCaptureFormats* formats) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (use_media_foundation_)
     GetDeviceSupportedFormatsMediaFoundation(device, formats);
   else
     GetDeviceSupportedFormatsDirectShow(device, formats);
 }
 
 }  // namespace media