Created VideoFramePool to avoid unnecessary VideoFrame alloc/free.

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 dc0932043b90a89e9e91ff801adb8db8c612732a..8a63cd3513fa888e95c639c7648e915244d9d5dc 100644
--- a/media/base/video_frame.h
+++ b/media/base/video_frame.h
@@ -169,6 +169,12 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
       base::TimeDelta timestamp,
       const base::Closure& no_longer_needed_cb);
 
+  // Wraps |frame| and calls |no_longer_needed_cb| when the wrapper VideoFrame
+  // gets destroyed.
+  static scoped_refptr<VideoFrame> WrapVideoFrame(
+      const scoped_refptr<VideoFrame>& frame,
+      const base::Closure& no_longer_needed_cb);
+
   // Creates a frame which indicates end-of-stream.
   static scoped_refptr<VideoFrame> CreateEOSFrame();