Move last of platform dependent init from //ui/gl to //ui/gl/init.

ui/gl/gl_implementation_win.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_implementation.h"
-
-#include "ui/gl/gl_context_stub_with_extensions.h"
-#include "ui/gl/gl_egl_api_implementation.h"
-#include "ui/gl/gl_gl_api_implementation.h"
-#include "ui/gl/gl_osmesa_api_implementation.h"
-#include "ui/gl/gl_wgl_api_implementation.h"
-
-namespace gl {
-
-void GetAllowedGLImplementations(std::vector<GLImplementation>* impls) {
-  impls->push_back(kGLImplementationEGLGLES2);
-  impls->push_back(kGLImplementationDesktopGL);
-  impls->push_back(kGLImplementationOSMesaGL);
-}
-
-bool GetGLWindowSystemBindingInfo(GLWindowSystemBindingInfo* info) {
-  switch (GetGLImplementation()) {
-    case kGLImplementationDesktopGL:
-      return GetGLWindowSystemBindingInfoWGL(info);
-    case kGLImplementationEGLGLES2:
-      return GetGLWindowSystemBindingInfoEGL(info);
-    default:
-      return false;
-  }
-}
-
-}  // namespace gl