Ensure GL initialization only happens once, and provide common init path

ui/gl/gl_surface.h

 // 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_GL_SURFACE_H_
 #define UI_GL_GL_SURFACE_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 52 matching lines @@
   bool HasExtension(const char* name);
 
   // Returns the internal frame buffer object name if the surface is backed by
   // FBO. Otherwise returns 0.
   virtual unsigned int GetBackingFrameBufferObject();
 
   // Copy part of the backbuffer to the frontbuffer.
   virtual bool PostSubBuffer(int x, int y, int width, int height);
 
   static bool InitializeOneOff();
+  static void InitializeOneOffForTests();
+  static void InitializeOneOffWithMockBindingsForTests();
+  static void InitializeDynamicMockBindingsForTests(GLContext* context);
 
   // Called after a context is made current with this surface. Returns false
   // on error.
   virtual bool OnMakeCurrent(GLContext* context);
 
   // Used for explicit buffer management.
   virtual bool SetBackbufferAllocation(bool allocated);
   virtual void SetFrontbufferAllocation(bool allocated);
 
   // Get a handle used to share the surface with another process. Returns null
@@ skipping 72 matching lines @@
 
  private:
   scoped_refptr<GLSurface> surface_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceAdapter);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_H_