Don't use GetAsTabContents. Send notifications from TabContentsView instead.

chrome/browser/extensions/extension_host.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/extensions/extension_host.h"
 
 #include <list>
 
 #include "base/message_loop.h"
 #include "base/singleton.h"
@@ skipping 515 matching lines @@
     extension_function_dispatcher_->HandleRequest(params);
   }
 }
 
 RenderViewHostDelegate::View* ExtensionHost::GetViewDelegate() {
   return this;
 }
 
 void ExtensionHost::CreateNewWindow(
     int route_id,
-    WindowContainerType window_container_type,
-    const string16& frame_name) {
+    const ViewHostMsg_CreateWindow_Params& params) {
   // TODO(aa): Use the browser's profile if the extension is split mode
   // incognito.
   TabContents* new_contents = delegate_view_helper_.CreateNewWindow(
       route_id,
       render_view_host()->process()->profile(),
       site_instance(),
       DOMUIFactory::GetDOMUIType(render_view_host()->process()->profile(),
           url_),
       this,
-      window_container_type,
-      frame_name);
+      params.window_container_type,
+      params.frame_name);
 
   TabContents* associated_contents = associated_tab_contents();
   if (associated_contents && associated_contents->delegate())
     associated_contents->delegate()->TabContentsCreated(new_contents);
 }
 
 void ExtensionHost::CreateNewWidget(int route_id,
                                     WebKit::WebPopupType popup_type) {
   CreateNewWidgetInternal(route_id, popup_type);
 }
@@ skipping 237 matching lines @@
     // Extensions hosted in ExternalTabContainer objects may not have
     // an associated browser.
     const Browser* browser = GetBrowser();
     if (browser)
       window_id = ExtensionTabUtil::GetWindowId(browser);
   } else if (extension_host_type_ != ViewType::EXTENSION_BACKGROUND_PAGE) {
     NOTREACHED();
   }
   return window_id;
 }