Pass camera facing to WebKit

content/renderer/media/media_stream_video_source.h

Index: content/renderer/media/media_stream_video_source.h
diff --git a/content/renderer/media/media_stream_video_source.h b/content/renderer/media/media_stream_video_source.h
index 666aced76582e7a44d0f4ec7286d44071300ace0..8836c2e7f6579a4d71a0c98034d0a02b2da2b8cf 100644
--- a/content/renderer/media/media_stream_video_source.h
+++ b/content/renderer/media/media_stream_video_source.h
@@ -89,6 +89,10 @@ class CONTENT_EXPORT MediaStreamVideoSource
     return weak_factory_.GetWeakPtr();
   }
 
+  virtual media::CameraFacing GetCameraFacing() {
+    return media::CameraFacing::DEFAULT;
+  }
+
  protected:
   void DoStopSource() override;