Allow wrapping a media::VideoFrame with a new view_rect.

media/base/video_frame.h

Index: media/base/video_frame.h
diff --git a/media/base/video_frame.h b/media/base/video_frame.h
index 0ff6f9856ead06c2eeaa6380549e3ac05b116156..568424324e392c8d4240911d01c013783b4971c9 100644
--- a/media/base/video_frame.h
+++ b/media/base/video_frame.h
@@ -150,9 +150,11 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
       const base::Closure& no_longer_needed_cb);
 
   // Wraps |frame| and calls |no_longer_needed_cb| when the wrapper VideoFrame
-  // gets destroyed.
+  // gets destroyed. |visible_rect| must be a sub rect within
+  // frame->visible_rect().
   static scoped_refptr<VideoFrame> WrapVideoFrame(
       const scoped_refptr<VideoFrame>& frame,
+      const gfx::Rect& visible_rect,
       const base::Closure& no_longer_needed_cb);
 
   // Creates a frame which indicates end-of-stream.