Revert of Refactor context creation parameters into a struct.

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/gpu_preference.h"
 #include "ui/gl/init/gl_init_export.h"
 
 namespace gl {
 
 class GLContext;
-struct GLContextAttribs;
 class GLShareGroup;
 class GLSurface;
 
 namespace init {
 
 // Returns a list of allowed GL implementations. The default implementation will
 // be the first item.
 GL_INIT_EXPORT std::vector<GLImplementation> GetAllowedGLImplementations();
 
 // Initializes GL bindings.
@@ skipping 13 matching lines @@
 // EGL, GLX, WGL). Returns true if the information was retrieved successfully.
 GL_INIT_EXPORT bool GetGLWindowSystemBindingInfo(
     GLWindowSystemBindingInfo* info);
 
 // Creates a GL context that is compatible with the given surface.
 // |share_group|, if non-null, is a group of contexts which the internally
 // created OpenGL context shares textures and other resources.
 GL_INIT_EXPORT scoped_refptr<GLContext> CreateGLContext(
     GLShareGroup* share_group,
     GLSurface* compatible_surface,
-    const GLContextAttribs& attribs);
+    GpuPreference gpu_preference);
 
 // Creates a GL surface that renders directly to a view.
 GL_INIT_EXPORT scoped_refptr<GLSurface> CreateViewGLSurface(
     gfx::AcceleratedWidget window);
 
 #if defined(USE_OZONE)
 // Creates a GL surface that renders directly into a window with surfaceless
 // semantics - there is no default framebuffer and the primary surface must
 // 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);
 
 }  // namespace init
 }  // namespace gl
 
 #endif  // UI_GL_INIT_GL_FACTORY_H_