VideoCaptureDeviceWin: Extract class-static method into a Factory (both MF/DS)

media/video/capture/video_capture_device_factory.cc

Index: media/video/capture/video_capture_device_factory.cc
diff --git a/media/video/capture/video_capture_device_factory.cc b/media/video/capture/video_capture_device_factory.cc
index 661900c4118f11091462c670f43e4e6420af02dc..c8e6b2bc5ff760c423b5ff29699da3e820c76a79 100644
--- a/media/video/capture/video_capture_device_factory.cc
+++ b/media/video/capture/video_capture_device_factory.cc
@@ -11,6 +11,8 @@
 
 #if defined(OS_MACOSX)
 #include "media/video/capture/mac/video_capture_device_factory_mac.h"
+#elif defined(OS_WIN)
+#include "media/video/capture/win/video_capture_device_factory_win.h"
 #endif
 
 namespace media {
@@ -33,6 +35,9 @@ scoped_ptr<VideoCaptureDeviceFactory>
 #if defined(OS_MACOSX)
     return scoped_ptr<VideoCaptureDeviceFactory>(new
         VideoCaptureDeviceFactoryMac());
+#elif defined(OS_WIN)
+    return scoped_ptr<VideoCaptureDeviceFactory>(new
+        VideoCaptureDeviceFactoryWin());
 #else
     return scoped_ptr<VideoCaptureDeviceFactory>(new
         VideoCaptureDeviceFactory());