FakeVideoCaptureDevice: add support for capturing into Dma-Bufs using VGEM in CrOs

media/video/capture/video_capture_device.h

Index: media/video/capture/video_capture_device.h
diff --git a/media/video/capture/video_capture_device.h b/media/video/capture/video_capture_device.h
index 41a1d771d11602ccf74841d46b3cbb020390798e..8051413cac1ea4186e17a43f06113798d60dffd1 100644
--- a/media/video/capture/video_capture_device.h
+++ b/media/video/capture/video_capture_device.h
@@ -15,6 +15,7 @@
 #include <list>
 #include <string>
 
+#include "base/files/file.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ -203,6 +204,7 @@ class MEDIA_EXPORT VideoCaptureDevice {
       virtual size_t size() const = 0;
       virtual void* data() = 0;
       virtual gfx::GpuMemoryBufferType GetType() = 0;
+      virtual base::PlatformFile AsPlatformFile() = 0;
       virtual ClientBuffer AsClientBuffer() = 0;
     };