Use factory method to create VideoCaptureDeviceFactory .

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 441 matching lines @@
 void VideoCaptureDeviceFactoryWin::GetDeviceSupportedFormats(
     const Name& device,
     VideoCaptureFormats* formats) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (use_media_foundation_)
     GetDeviceSupportedFormatsMediaFoundation(device, formats);
   else
     GetDeviceSupportedFormatsDirectShow(device, formats);
 }
 
+// static
+VideoCaptureDeviceFactory*
+VideoCaptureDeviceFactory::CreateVideoCaptureDeviceFactory(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
+  return new VideoCaptureDeviceFactoryWin();
+}
+
 }  // namespace media