Refactor GL surface format handling

ui/gl/init/gl_factory.h

 // 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.
 
 #ifndef UI_GL_INIT_GL_FACTORY_H_
 #define UI_GL_INIT_GL_FACTORY_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_surface_format.h"
 #include "ui/gl/gpu_preference.h"
 #include "ui/gl/init/gl_init_export.h"
 
 namespace gl {
 
 class GLContext;
 struct GLContextAttribs;
 class GLShareGroup;
 class GLSurface;
 
@@ skipping 39 matching lines @@
 // be presented as an overlay. If surfaceless mode is not supported or
 // enabled it will return a null pointer.
 GL_INIT_EXPORT scoped_refptr<GLSurface> CreateSurfacelessViewGLSurface(
     gfx::AcceleratedWidget window);
 #endif  // defined(USE_OZONE)
 
 // Creates a GL surface used for offscreen rendering.
 GL_INIT_EXPORT scoped_refptr<GLSurface> CreateOffscreenGLSurface(
     const gfx::Size& size);
 
+GL_INIT_EXPORT scoped_refptr<GLSurface> CreateOffscreenGLSurfaceWithFormat(
+    const gfx::Size& size, GLSurfaceFormat format);
+
 }  // namespace init
 }  // namespace gl
 
 #endif  // UI_GL_INIT_GL_FACTORY_H_