gpu: introduce glCopySubTextureCHROMIUM

gpu/blink/webgraphicscontext3d_impl.h

Index: gpu/blink/webgraphicscontext3d_impl.h
diff --git a/gpu/blink/webgraphicscontext3d_impl.h b/gpu/blink/webgraphicscontext3d_impl.h
index ff2ca9707627dee98b1680931f59e27ba1d8e307..a0d14612b3d0c8fe1f79e784edc6692cb06db269 100644
--- a/gpu/blink/webgraphicscontext3d_impl.h
+++ b/gpu/blink/webgraphicscontext3d_impl.h
@@ -451,11 +451,33 @@ class GPU_BLINK_EXPORT WebGraphicsContext3DImpl
   virtual void getQueryObjectuivEXT(
       WebGLId query, WGC3Denum pname, WGC3Duint* params);
 
-  virtual void copyTextureCHROMIUM(WGC3Denum target, WebGLId source_id,
-                                   WebGLId dest_id, WGC3Dint level,
+  // TODO(dshwang): Remove |level| in Blink and then remove it.
+  void copyTextureCHROMIUM(WGC3Denum target,
+                           WebGLId source_id,
+                           WebGLId dest_id,
+                           WGC3Dint level,
+                           WGC3Denum internal_format,
+                           WGC3Denum dest_type) override;
+
+  void copySubTextureCHROMIUM(WGC3Denum target,
+                              WebGLId source_id,
+                              WebGLId dest_id,
+                              WGC3Dint level,
+                              WGC3Dint xoffset,
+                              WGC3Dint yoffset) override;
+
+  virtual void copyTextureCHROMIUM(WGC3Denum target,
+                                   WebGLId source_id,
+                                   WebGLId dest_id,
                                    WGC3Denum internal_format,
                                    WGC3Denum dest_type);
 
+  virtual void copySubTextureCHROMIUM(WGC3Denum target,
+                                      WebGLId sourceId,
+                                      WebGLId destId,
+                                      WGC3Dint xoffset,
+                                      WGC3Dint yoffset);
+
   virtual void bindUniformLocationCHROMIUM(WebGLId program, WGC3Dint location,
                                            const WGC3Dchar* uniform);