Top level navigations are not sent to the host browser in the ChromeFrame NPA...

chrome_frame/chrome_frame_npapi.h

 // Copyright (c) 2009 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 CHROME_FRAME_CHROME_FRAME_NPAPI_H_
 #define CHROME_FRAME_CHROME_FRAME_NPAPI_H_
 
 #include <atlbase.h>
 #include <atlwin.h>
 #include <string>
@@ skipping 114 matching lines @@
 
   // Initialize string->identifier mapping, public to allow unittesting.
   static void InitializeIdentifiers();
 
   bool HandleContextMenuCommand(UINT cmd, const IPC::ContextMenuParams& params);
  protected:
   // Handler for accelerator messages passed on from the hosted chrome
   // instance.
   virtual void OnAcceleratorPressed(int tab_handle, const MSG& accel_message);
   virtual void OnTabbedOut(int tab_handle, bool reverse);
-  virtual void OnOpenURL(int tab_handle, const GURL& url, int open_disposition);
+  virtual void OnOpenURL(int tab_handle, const GURL& url,
+                         const GURL& referrer, int open_disposition);
   virtual void OnLoad(int tab_handle, const GURL& url);
   virtual void OnMessageFromChromeFrame(int tab_handle,
                                         const std::string& message,
                                         const std::string& origin,
                                         const std::string& target);
   // ChromeFrameDelegate overrides
   virtual void OnLoadFailed(int error_code, const std::string& url);
   virtual void OnAutomationServerReady();
   virtual void OnAutomationServerLaunchFailed(
       AutomationLaunchResult reason, const std::string& server_version);
@@ skipping 193 matching lines @@
   // The value of src property keeping the current URL.
   std::string src_;
   // Used to fetch network resources when host network stack is in use.
   NPAPIUrlRequestManager url_fetcher_;
 
   // Set if we receive a navigation request before initializing Chrome.
   bool navigate_after_initialization_;
 };
 
 #endif  // CHROME_FRAME_CHROME_FRAME_NPAPI_H_