Persist Instance ID data to GCM store.

components/gcm_driver/instance_id/instance_id.h

 // Copyright 2015 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_INSTANCE_ID_INSTANCE_ID_H_
 #define COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_H_
 
 #include <map>
 #include <string>
 
@@ skipping 23 matching lines @@
     NETWORK_ERROR,
     // Problem at the server.
     SERVER_ERROR,
     // Other errors.
     UNKNOWN_ERROR
   };
 
   // Asynchronous callbacks.
   typedef base::Callback<void(const std::string& app_id,
                               bool update_id)> TokenRefreshCallback;
+  typedef base::Callback<void(const std::string& id)> GetIDCallback;
+  typedef base::Callback<void(const base::Time& creation_time)>
+      GetCreationTimeCallback;
   typedef base::Callback<void(const std::string& token,
                               Result result)> GetTokenCallback;
   typedef base::Callback<void(Result result)> DeleteTokenCallback;
   typedef base::Callback<void(Result result)> DeleteIDCallback;
 
   static const int kInstanceIDByteLength = 8;
 
   // Creator.
   // |app_id|: identifies the application that uses the Instance ID.
   // |gcm_driver|: driver to access the GCM functionalities needed to support
   //               Instance ID.
   static InstanceID* Create(const std::string& app_id,
                             gcm::GCMDriver* gcm_driver);
 
   virtual ~InstanceID();
 
   // Sets the callback that will be invoked when the token refresh event needs
   // to be triggered.
   void SetTokenRefreshCallback(const TokenRefreshCallback& callback);
 
   // Returns the Instance ID.
-  virtual std::string GetID() = 0;
+  virtual void GetID(const GetIDCallback& callback) = 0;
 
   // Returns the time when the InstanceID has been generated.
-  virtual base::Time GetCreationTime() = 0;
+  virtual void GetCreationTime(const GetCreationTimeCallback& callback) = 0;
 
   // Retrieves a token that allows the authorized entity to access the service
   // defined as "scope".
   // |authorized_entity|: identifies the entity that is authorized to access
   //                      resources associated with this Instance ID. It can be
   //                      another Instance ID or a project ID.
   // |scope|: identifies authorized actions that the authorized entity can take.
   //          E.g. for sending GCM messages, "GCM" scope should be used.
   // |options|: allows including a small number of string key/value pairs that
   //            will be associated with the token and may be used in processing
@@ skipping 28 matching lines @@
  private:
   std::string app_id_;
   TokenRefreshCallback token_refresh_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceID);
 };
 
 }  // namespace instance_id
 
 #endif  // COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_H_