Split GL binding init into core and extension part

ui/gfx/gl/gl_context.h

 // Copyright (c) 2011 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_GFX_GL_GL_CONTEXT_H_
 #define UI_GFX_GL_GL_CONTEXT_H_
 #pragma once
 
 #include <string>
 
@@ skipping 59 matching lines @@
   static bool SupportsDualGpus();
 
   static GLContext* GetCurrent();
 
   virtual bool WasAllocatedUsingARBRobustness();
 
  protected:
   virtual ~GLContext();
   static void SetCurrent(GLContext* context, GLSurface* surface);
 
+  // Initialize function pointers to extension functions in the GL
+  // implementation. Should be called immediately after this context is made
+  // current.
+  bool InitializeExtensionBindings();
+
  private:
   scoped_refptr<GLShareGroup> share_group_;
   friend class base::RefCounted<GLContext>;
   DISALLOW_COPY_AND_ASSIGN(GLContext);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GL_GL_CONTEXT_H_