Implement native GMB backbuffers in the GLES2 Command Decoder.

gpu/command_buffer/service/image_factory.cc

 // Copyright 2014 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 "gpu/command_buffer/service/image_factory.h"
 
+#include "ui/gl/gl_image.h"
+
 namespace gpu {
 
 ImageFactory::ImageFactory() {
 }
 
 ImageFactory::~ImageFactory() {
 }
 
+scoped_refptr<gl::GLImage> ImageFactory::CreateAnonymousImage(
+    const gfx::Size& size,
+    gfx::BufferFormat format,
+    unsigned internalformat) {
+  NOTREACHED();
+  return nullptr;
+}
+
+unsigned ImageFactory::RequiredTextureType() {
+  NOTREACHED();

[piman, 2016/06/27 22:46:15]

nit: this is reached on !mac if the client requests GMB backbuffers.
NOTIMPLEMENTED() instead?

[erikchen, 2016/06/28 01:38:42]

Done.

+  return 0;
+}
+
+bool ImageFactory::SupportsFormatRGB() {
+  return true;
+}
+
 }  // namespace gpu