WebGL: optimize webgl.texSubImage2D(video) path. (Blink side)

Source/core/html/HTMLVideoElement.h

Index: Source/core/html/HTMLVideoElement.h
diff --git a/Source/core/html/HTMLVideoElement.h b/Source/core/html/HTMLVideoElement.h
index 54a56ea19e21c83c4b8e10e492b321be84e5dd8a..8bf4ee2ee7d5383a49cd38571e9fa4cd8e848a41 100644
--- a/Source/core/html/HTMLVideoElement.h
+++ b/Source/core/html/HTMLVideoElement.h
@@ -69,7 +69,10 @@ public:
     void paintCurrentFrame(SkCanvas*, const IntRect&, const SkPaint*) const;
 
     // Used by WebGL to do GPU-GPU textures copy if possible.
-    bool copyVideoTextureToPlatformTexture(WebGraphicsContext3D*, Platform3DObject texture, GLenum internalFormat, GLenum type, bool premultiplyAlpha, bool flipY);
+    bool copyVideoTextureToPlatformTexture(WebGraphicsContext3D*, GLenum target, Platform3DObject texture,
+        GLenum internalFormat, GLenum type, GLint level, bool premultiplyAlpha, bool flipY);
+    bool copyVideoSubTextureToPlatformTexture(WebGraphicsContext3D*, GLenum target, Platform3DObject texture,
+        GLint level, GLint xoffset, GLint yoffset, bool premultiplyAlpha, bool flipY);
 
     bool shouldDisplayPosterImage() const { return displayMode() == Poster; }