Allow a Views client to provide a default frameview for window widgets.

ui/views/views_delegate.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_VIEWS_VIEWS_DELEGATE_H_
 #define UI_VIEWS_VIEWS_DELEGATE_H_
 #pragma once
 
 #include <string>
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #include "base/string16.h"
 #include "ui/base/accessibility/accessibility_types.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace ui {
 class Clipboard;
 }
 
 namespace views {
 
+class NonClientFrameView;
 class View;
 class Widget;
 
 // ViewsDelegate is an interface implemented by an object using the views
 // framework. It is used to obtain various high level application utilities
 // and perform some actions such as window placement saving.
 //
 // The embedding app must set views_delegate to assign its ViewsDelegate
 // implementation.
 class VIEWS_EXPORT ViewsDelegate {
@@ skipping 30 matching lines @@
                                      const string16& menu_item_name,
                                      int item_index,
                                      int item_count,
                                      bool has_submenu) = 0;
 
 #if defined(OS_WIN)
   // Retrieves the default window icon to use for windows if none is specified.
   virtual HICON GetDefaultWindowIcon() const = 0;
 #endif
 
+  // Creates a default NonClientFrameView to be used for windows that don't
+  // specify their own. If this function returns NULL, the
+  // views::CustomFrameView type will be used.
+  virtual NonClientFrameView* CreateDefaultNonClientFrameView(
+      Widget* widget) = 0;
+
   // AddRef/ReleaseRef are invoked while a menu is visible. They are used to
   // ensure we don't attempt to exit while a menu is showing.
   virtual void AddRef() = 0;
   virtual void ReleaseRef() = 0;
 
   // Converts views::Event::flags to a WindowOpenDisposition.
   virtual int GetDispositionForEvent(int event_flags) = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEWS_DELEGATE_H_