MacViews: Change Widget context type to NativeWindow

ui/views/examples/examples_window_with_content.cc

 // 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.
 
 #include "ui/views/examples/examples_window_with_content.h"
 
 #include "content/public/browser/browser_context.h"
 #include "ui/views/examples/webview_example.h"
 
 namespace views {
 namespace examples {
 
 void ShowExamplesWindowWithContent(Operation operation,
                                    content::BrowserContext* browser_context,
-                                   gfx::NativeView window_context) {
+                                   gfx::NativeWindow window_context) {
   scoped_ptr<ScopedVector<ExampleBase> > extra_examples(
       new ScopedVector<ExampleBase>);
   extra_examples->push_back(new WebViewExample(browser_context));
   ShowExamplesWindow(operation, window_context, extra_examples.Pass());
 }
 
 }  // namespace examples
 }  // namespace views