Keep a web dialog window centered over the content area

chrome/browser/ui/views/native_constrained_window_aura.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 "chrome/browser/ui/views/constrained_window_views.h"
 
+#include "ui/aura/client/aura_constants.h"
+#include "ui/aura/window.h"
 #include "ui/views/widget/native_widget_aura.h"
 
 class NativeConstrainedWindowAura : public NativeConstrainedWindow,
                                     public views::NativeWidgetAura {
  public:
   explicit NativeConstrainedWindowAura(
       NativeConstrainedWindowDelegate* delegate)
       : views::NativeWidgetAura(delegate->AsNativeWidgetDelegate()),
         delegate_(delegate) {
+    GetNativeWindow()->SetProperty(aura::client::kConstrainedWindowKey, true);
   }
 
   virtual ~NativeConstrainedWindowAura() {
   }
 
  private:
   // Overridden from NativeConstrainedWindow:
   virtual views::NativeWidget* AsNativeWidget() OVERRIDE {
     return this;
   }
@@ skipping 10 matching lines @@
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeConstrainedWindow, public:
 
 // static
 NativeConstrainedWindow* NativeConstrainedWindow::CreateNativeConstrainedWindow(
     NativeConstrainedWindowDelegate* delegate) {
   return new NativeConstrainedWindowAura(delegate);
 }