Offset scissor and viewport when using SetDrawRectangle on surface.

ui/gl/gl_surface_stub.cc

 // 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.
 
 #include "ui/gl/gl_surface_stub.h"
 
 namespace gl {
 
 void GLSurfaceStub::Destroy() {
 }
@@ skipping 21 matching lines @@
 }
 
 bool GLSurfaceStub::BuffersFlipped() const {
   return buffers_flipped_;
 }
 
 GLSurfaceFormat GLSurfaceStub::GetFormat() {
   return GLSurfaceFormat();
 }
 
+bool GLSurfaceStub::SupportsSetDrawRectangle() const {
+  return supports_draw_rectangle_;
+}
+
+gfx::Vector2d GLSurfaceStub::GetDrawOffset() const {
+  return supports_draw_rectangle_ ? gfx::Vector2d(100, 200) : gfx::Vector2d();
+}
+
 GLSurfaceStub::~GLSurfaceStub() {}
 
 }  // namespace gl