Add a basic NativeViewportMac for Mojo

ui/gl/gl_surface_nsview.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_NSVIEW_H_
 #define UI_GL_GL_SURFACE_NSVIEW_H_
 
 #include "base/compiler_specific.h"
 #include "ui/gfx/size.h"
 #include "ui/gl/gl_surface.h"
 
 namespace gfx {
 
 class GLContextNSView;
 
 // GLSurfaceNSView provides an implementation of the the GLSurface interface
 // that is backed by an NSView.  This interface pairs with the GLContextNSView
 // class, and the NSView is expected to use this context for drawing.
-class GLSurfaceNSView : public GLSurface {
+class GL_EXPORT GLSurfaceNSView : public GLSurface {
  public:
   explicit GLSurfaceNSView(AcceleratedWidget view);
-  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|.
   virtual bool OnMakeCurrent(GLContext* context) OVERRIDE;
 
  private:
+  virtual ~GLSurfaceNSView();
+
   // Weak.  An |NSView*|.
   AcceleratedWidget view_;
 
   // Weak.  Associated context.
   GLContextNSView* context_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceNSView);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_NSVIEW_H_