Optimize webgl texImage2D from YUV video textures.

media/renderers/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_RENDERERS_SKCANVAS_VIDEO_RENDERER_H_
 #define MEDIA_RENDERERS_SKCANVAS_VIDEO_RENDERER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 60 matching lines @@
   // The format of |video_frame| must be VideoFrame::NATIVE_TEXTURE.
   static void CopyVideoFrameSingleTextureToGLTexture(
       gpu::gles2::GLES2Interface* gl,
       VideoFrame* video_frame,
       unsigned int texture,
       unsigned int internal_format,
       unsigned int type,
       bool premultiply_alpha,
       bool flip_y);
 
+  // Copy the contents of texture of |video_frame| to texture |texture| in
+  // context |destination_gl|.
+  // |level|, |internal_format|, |type| specify target texture |texture|.
+  // The format of |video_frame| must be VideoFrame::NATIVE_TEXTURE.
+  // |context_3d| has a GrContext that may be used during the copy.
+  // Returns true on success.
+  bool CopyVideoFrameTexturesToGLTexture(
+      const Context3D& context_3d,
+      gpu::gles2::GLES2Interface* destination_gl,
+      const scoped_refptr<VideoFrame>& video_frame,
+      unsigned int texture,
+      unsigned int internal_format,
+      unsigned int type,
+      bool premultiply_alpha,
+      bool flip_y);
+
   // In general, We hold the most recently painted frame to increase the
   // performance for the case that the same frame needs to be painted
   // repeatedly. Call this function if you are sure the most recent frame will
   // never be painted again, so we can release the resource.
   void ResetCache();
 
  private:
+  // Update the cache holding the most-recently-painted frame.
+  void UpdateLastImage(const scoped_refptr<VideoFrame>& video_frame,
+                       const Context3D& context_3d);
+
   // Last image used to draw to the canvas.
   sk_sp<SkImage> last_image_;
   // Timestamp of the videoframe used to generate |last_image_|.
   base::TimeDelta last_timestamp_ = media::kNoTimestamp();
   // If |last_image_| is not used for a while, it's deleted to save memory.
   base::DelayTimer last_image_deleting_timer_;
 
   // Used for DCHECKs to ensure method calls executed in the correct thread.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SkCanvasVideoRenderer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_SKCANVAS_VIDEO_RENDERER_H_