GLContextNSView should not assume concrete type GLSurface is GLSurfaceNSView

ui/gfx/gl/gl_surface_nsview.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_SURFACE_NSVIEW_H_
 #define UI_GFX_GL_GL_SURFACE_NSVIEW_H_
 
 #include "base/compiler_specific.h"
 #include "ui/gfx/gl/gl_surface.h"
 #include "ui/gfx/size.h"
@@ skipping 11 matching lines @@
   virtual ~GLSurfaceNSView();
 
   // GLSurface:
   virtual void Destroy() OVERRIDE;
   virtual bool IsOffscreen() OVERRIDE;
   virtual bool SwapBuffers() OVERRIDE;
   virtual gfx::Size GetSize() OVERRIDE;
   virtual void* GetHandle() OVERRIDE;
 
   // Allow the surface to call back to context when in need of |FlushBuffer|.
-  void SetGLContext(GLContextNSView* context);
+  virtual bool OnMakeCurrent(GLContext* context) OVERRIDE;
 
  private:
   // Weak.  An |NSView*|.
   PluginWindowHandle view_;
 
   // Weak.  Associated context.
   GLContextNSView* context_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceNSView);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GL_GL_SURFACE_NSVIEW_H_