Use SkSrc_Mode in SkCanvasVideoRenderer, to prevent transparent video frames from blending with reu…

media/base/video_frame.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_VIDEO_FRAME_H_
 #define MEDIA_BASE_VIDEO_FRAME_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 171 matching lines @@
   // Allocates YV12 frame based on |size|, and sets its data to the YUV(y,u,v).
   static scoped_refptr<VideoFrame> CreateColorFrame(
       const gfx::Size& size,
       uint8 y, uint8 u, uint8 v,
       base::TimeDelta timestamp);
 
   // Allocates YV12 frame based on |size|, and sets its data to the YUV
   // equivalent of RGB(0,0,0).
   static scoped_refptr<VideoFrame> CreateBlackFrame(const gfx::Size& size);
 
+  // Allocates YV12A frame based on |size|, and sets its data to the YUVA
+  // equivalent of RGBA(0,0,0,0).
+  static scoped_refptr<VideoFrame> CreateTransparentFrame(
+      const gfx::Size& size);
+
 #if defined(VIDEO_HOLE)
   // Allocates a hole frame.
   static scoped_refptr<VideoFrame> CreateHoleFrame(const gfx::Size& size);
 #endif  // defined(VIDEO_HOLE)
 
   static size_t NumPlanes(Format format);
 
   // Returns the required allocation size for a (tightly packed) frame of the
   // given coded size and format.
   static size_t AllocationSize(Format format, const gfx::Size& coded_size);
@@ skipping 131 matching lines @@
   std::vector<uint32> release_sync_points_;
 
   const bool end_of_stream_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoFrame);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_FRAME_H_