Clear GCM data when the user clears cookies and other site data

components/gcm_driver/gcm_driver.h

 // Copyright 2014 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 COMPONENTS_GCM_DRIVER_GCM_DRIVER_H_
 #define COMPONENTS_GCM_DRIVER_GCM_DRIVER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 54 matching lines @@
             const std::string& receiver_id,
             const GCMClient::OutgoingMessage& message,
             const SendCallback& callback);
 
   const GCMAppHandlerMap& app_handlers() const { return app_handlers_; }
 
   // This method must be called before destroying the GCMDriver. Once it has
   // been called, no other GCMDriver methods may be used.
   virtual void Shutdown();
 
-  // Call this method when the user signs in to a GAIA account.
-  // TODO(jianli): To be removed when sign-in enforcement is dropped.
+  // Called when the user signs in to or out of a GAIA account.
   virtual void OnSignedIn() = 0;
+  virtual void OnSignedOut() = 0;
 
   // Removes all the cached and persisted GCM data. If the GCM service is
   // restarted after the purge, a new Android ID will be obtained.
   virtual void Purge() = 0;
 
   // Adds a handler for a given app.
   virtual void AddAppHandler(const std::string& app_id, GCMAppHandler* handler);
 
   // Remove the handler for a given app.
   virtual void RemoveAppHandler(const std::string& app_id);
@@ skipping 91 matching lines @@
 
   // The default handler when no app handler can be found in the map.
   DefaultGCMAppHandler default_app_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMDriver);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_GCM_DRIVER_H_