When Chrome hands off a URL to be opened by the external host by the ViewHost...

chrome/browser/automation/automation_provider.h

 // Copyright (c) 2006-2008 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.
 
 // This implements a browser-side endpoint for UI automation activity.
 // The client-side endpoint is implemented by AutomationProxy.
 // The entire lifetime of this object should be contained within that of
 // the BrowserProcess, and in particular the NotificationService that's
 // hung off of it.
 
@@ skipping 285 matching lines @@
                          int* tab_handle);
 
   void ConnectExternalTab(intptr_t cookie,
                           gfx::NativeWindow* tab_container_window,
                           gfx::NativeWindow* tab_window,
                           int* tab_handle);
 
   void OnSetPageFontSize(int tab_handle, int font_size);
 
   void NavigateInExternalTab(
-      int handle, const GURL& url,
+      int handle, const GURL& url, const GURL& referrer,
       AutomationMsg_NavigationResponseValues* status);
   void NavigateExternalTabAtIndex(
       int handle, int index, AutomationMsg_NavigationResponseValues* status);
 
 // TODO(port): remove windowisms.
 #if defined(OS_WIN)
   // The container of an externally hosted tab calls this to reflect any
   // accelerator keys that it did not process. This gives the tab a chance
   // to handle the keys
   void ProcessUnhandledAccelerator(const IPC::Message& message, int handle,
@@ skipping 252 matching lines @@
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   void OnRemoveProvider();  // Called via PostTask
 
   NotificationRegistrar registrar_;
 };
 
 #endif  // CHROME_BROWSER_AUTOMATION_AUTOMATION_PROVIDER_H_