Refactor GL surface format handling

ui/gl/init/gl_factory.cc

 // Copyright 2016 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/init/gl_factory.h"
 
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 71 matching lines @@
   return initialized;
 }
 
 void ShutdownGL() {
   ShutdownGLPlatform();
 
   SetGLImplementation(kGLImplementationNone);
   UnloadGLNativeLibraries();
 }
 
+scoped_refptr<GLSurface> CreateOffscreenGLSurface(const gfx::Size& size) {
+  return CreateOffscreenGLSurfaceWithFormat(size, GLSurfaceFormat());
+}
+
 }  // namespace init
 }  // namespace gl