Revert to zero-initializing buffers for FFmpegVideoDecoder

media/base/video_frame_pool.h

Index: media/base/video_frame_pool.h
diff --git a/media/base/video_frame_pool.h b/media/base/video_frame_pool.h
index 947e8afd4fd6cfd819c45d743894c54a75cc9d60..d5c1690e9b567b9302667b6e879a0e8ff1e6d2c6 100644
--- a/media/base/video_frame_pool.h
+++ b/media/base/video_frame_pool.h
@@ -25,7 +25,9 @@ class MEDIA_EXPORT VideoFramePool {
 
   // Returns a frame from the pool that matches the specified
   // parameters or creates a new frame if no suitable frame exists in
-  // the pool.
+  // the pool. The pool is drained if no matching frame is found.
+  // The buffer for the new frame will be zero initialized.  Reused frames will
+  // not be zero initialized.
   scoped_refptr<VideoFrame> CreateFrame(VideoPixelFormat format,
                                         const gfx::Size& coded_size,
                                         const gfx::Rect& visible_rect,