Potential bug on drawing video on SkCanvas

media/filters/skcanvas_video_renderer.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_FILTERS_SKCANVAS_VIDEO_RENDERER_H_
 #define MEDIA_FILTERS_SKCANVAS_VIDEO_RENDERER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "media/base/media_export.h"
 #include "media/base/video_rotation.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/rect.h"
 
 class SkCanvas;
 
 namespace media {
 
@@ skipping 15 matching lines @@
              SkCanvas* canvas,
              const gfx::RectF& dest_rect,
              uint8 alpha,
              SkXfermode::Mode mode,
              VideoRotation video_rotation);
 
   // Copy |video_frame| on |canvas|.
   void Copy(const scoped_refptr<VideoFrame>&, SkCanvas* canvas);
 
  private:
-  VideoImageGenerator* generator_;
+  void ResetLastFrame();
+  void ResetAcceleratedLastFrame();
 
   // An RGB bitmap and corresponding timestamp of the previously converted
-  // video frame data.
+  // video frame data by software color space conversion.
   SkBitmap last_frame_;
   base::TimeDelta last_frame_timestamp_;
+  // If |last_frame_| is not used for a while, it's deleted to save memory.
+  base::DelayTimer<SkCanvasVideoRenderer> frame_deleting_timer_;
+
+  // This is a hardware accelerated copy of the frame generated by
+  // |accelerated_generator_|.
+  // It's used when |canvas| parameter in Paint() is Ganesh canvas.
+  // Note: all GrContext in SkCanvas instances are same.
+  SkBitmap accelerated_last_frame_;
+  VideoImageGenerator* accelerated_generator_;
+  base::TimeDelta accelerated_last_frame_timestamp_;
+  base::DelayTimer<SkCanvasVideoRenderer> accelerated_frame_deleting_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(SkCanvasVideoRenderer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_SKCANVAS_VIDEO_RENDERER_H_