webgl: optimize webgl.texSubImage2D(video) path.

media/blink/webmediaplayer_impl.h

Index: media/blink/webmediaplayer_impl.h
diff --git a/media/blink/webmediaplayer_impl.h b/media/blink/webmediaplayer_impl.h
index 2f7516f7202c8c36384fe0998907c7b2d16e248a..3d4aaaca905d7b421d0e521b630c99ffe790bcc1 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -135,11 +135,32 @@ class MEDIA_EXPORT WebMediaPlayerImpl
   virtual unsigned audioDecodedByteCount() const;
   virtual unsigned videoDecodedByteCount() const;
 
+  // TODO(dshwang): remove it. virtual trick allows to remove it in blink.
+  // crbug.com/504773
+  virtual bool copyVideoTextureToPlatformTexture(
+      blink::WebGraphicsContext3D* web_graphics_context,
+      unsigned int texture,
+      unsigned int internal_format,
+      unsigned int type,
+      bool premultiply_alpha,
+      bool flip_y);
+
   bool copyVideoTextureToPlatformTexture(
       blink::WebGraphicsContext3D* web_graphics_context,
+      unsigned int target,
       unsigned int texture,
       unsigned int internal_format,
       unsigned int type,
+      int level,
+      bool premultiply_alpha,
+      bool flip_y) override;
+  bool copyVideoSubTextureToPlatformTexture(
+      blink::WebGraphicsContext3D* web_graphics_context,
+      unsigned int target,
+      unsigned int texture,
+      int level,
+      int xoffset,
+      int yoffset,
       bool premultiply_alpha,
       bool flip_y) override;