webgl: optimize webgl.texSubImage2D(video) path.

content/renderer/media/webmediaplayer_ms.h

Index: content/renderer/media/webmediaplayer_ms.h
diff --git a/content/renderer/media/webmediaplayer_ms.h b/content/renderer/media/webmediaplayer_ms.h
index dd0b5c5a8e636020e34fd5d96b9f7708c5e08fb2..be551c32a54cbf5f3cf41294f49abd18f9513400 100644
--- a/content/renderer/media/webmediaplayer_ms.h
+++ b/content/renderer/media/webmediaplayer_ms.h
@@ -117,11 +117,32 @@ class WebMediaPlayerMS
   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;