Stop trusting the sign-in process if it manages to navigate to another URL.

chrome/browser/signin/signin_manager.h

 // 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.
 //
 // The signin manager encapsulates some functionality tracking
 // which user is signed in. See SigninManagerBase for full description of
 // responsibilities. The class defined in this file provides functionality
 // required by all platforms except Chrome OS.
 //
 // When a user is signed in, a ClientLogin request is run on their behalf.
@@ skipping 168 matching lines @@
   // be invoked on the IO thread, and can be used to check if signin is enabled
   // on that thread.
   static bool IsSigninAllowedOnIOThread(ProfileIOData* io_data);
 
   // Allows the SigninManager to track the privileged signin process
   // identified by |process_id| so that we can later ask (via IsSigninProcess)
   // if it is safe to sign the user in from the current context (see
   // OneClickSigninHelper).  All of this tracking state is reset once the
   // renderer process terminates.
   void SetSigninProcess(int process_id);
+  void ClearSigninProcess();
   bool IsSigninProcess(int process_id) const;
   bool HasSigninProcess() const;
 
  protected:
   // If user was signed in, load tokens from DB if available.
   virtual void InitTokenService() OVERRIDE;
 
   // Flag saying whether signing out is allowed.
   bool prohibit_signout_;
 
@@ skipping 98 matching lines @@
 
   // Helper object to listen for changes to the signin allowed preference.
   BooleanPrefMember signin_allowed_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninManager);
 };
 
 #endif  // !defined(OS_CHROMEOS)
 
 #endif  // CHROME_BROWSER_SIGNIN_SIGNIN_MANAGER_H_