Make GL calls go through subclassable class.

ui/gl/gl_wgl_api_implementation.h

Index: ui/gl/gl_wgl_api_implementation.h
diff --git a/ui/gl/gl_wgl_api_implementation.h b/ui/gl/gl_wgl_api_implementation.h
new file mode 100644
index 0000000000000000000000000000000000000000..35afd0a5540f2e0ffab248951819e8b6ce349708
--- /dev/null
+++ b/ui/gl/gl_wgl_api_implementation.h
@@ -0,0 +1,40 @@
+// 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.
+
+#ifndef UI_GL_WGL_API_IMPLEMENTATION_H_
+#define UI_GL_WGL_API_IMPLEMENTATION_H_
+
+#include "base/compiler_specific.h"
+#include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_export.h"
+
+namespace gfx {
+
+class GLContext;
+
+void InitializeGLBindingsWGL();
+void InitializeGLExtensionBindingsWGL(GLContext* context);
+void InitializeDebugGLBindingsWGL();
+void ClearGLBindingsWGL();
+
+class GL_EXPORT RealWGLApi : public WGLApi {
+ public:
+  RealWGLApi();
+  void Initialize(DriverWGL* driver);
+
+  // Include the auto-generated part of this class. We split this because
+  // it means we can easily edit the non-auto generated parts right here in
+  // this file instead of having to edit some template or the code generator.
+  #include "gl_bindings_api_autogen_wgl.h"
+
+ private:
+  DriverWGL* driver_;
+};
+
+}  // namespace gfx
+
+#endif  // UI_GL_WGL_API_IMPLEMENTATION_H_
+
+
+