Require a default parent to use some Views implementations on Windows.

chrome/browser/ui/views/tab_contents/native_tab_contents_view_win.cc

 // 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.
 
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_win.h"
 
 #include "chrome/browser/renderer_host/render_widget_host_view_win.h"
 #include "chrome/browser/tab_contents/web_drop_target_win.h"
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_delegate.h"
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_views.h"
 #include "chrome/browser/ui/views/tab_contents/tab_contents_drag_win.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_view.h"
+#include "views/views_delegate.h"
 #include "views/widget/widget.h"
 
 namespace {
 
 // Tabs must be created as child widgets, otherwise they will be given
 // a FocusManager which will conflict with the FocusManager of the
 // window they eventually end up attached to.
 //
 // A tab will not have a parent HWND whenever it is not active in its
 // host window - for example at creation time and when it's in the
@@ skipping 311 matching lines @@
   }
   return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsView, public:
 
 // static
 NativeTabContentsView* NativeTabContentsView::CreateNativeTabContentsView(
     internal::NativeTabContentsViewDelegate* delegate) {
-  if (views::Widget::IsPureViews())
+  if (views::Widget::IsPureViews() &&
+      views::ViewsDelegate::views_delegate->GetDefaultParentView())
     return new NativeTabContentsViewViews(delegate);
   return new NativeTabContentsViewWin(delegate);
 }