[GCM] API update to allow only a single sender in registration

google_apis/gcm/gcm_client.h

 // Copyright 2013 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 GOOGLE_APIS_GCM_GCM_CLIENT_H_
 #define GOOGLE_APIS_GCM_GCM_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 144 matching lines @@
   virtual void Load() = 0;
 
   // Checks out of the GCM service. This will erase all the cached and persisted
   // data.
   virtual void CheckOut() = 0;
 
   // Registers the application for GCM. Delegate::OnRegisterFinished will be
   // called asynchronously upon completion.
   // |app_id|: application ID.
   // |cert|: SHA-1 of public key of the application, in base16 format.
-  // |sender_ids|: list of IDs of the servers that are allowed to send the
-  //               messages to the application. These IDs are assigned by the
-  //               Google API Console.
+  // |sender_id|: project ID of a server that is allowed to send messages to the
+  //              application. Project IDs are assigned by the Google API
+  //              Console.
   virtual void Register(const std::string& app_id,
                         const std::string& cert,
-                        const std::vector<std::string>& sender_ids) = 0;
+                        const std::string& sender_id) = 0;
 
   // Unregisters the application from GCM when it is uninstalled.
   // Delegate::OnUnregisterFinished will be called asynchronously upon
   // completion.
   // |app_id|: application ID.
   virtual void Unregister(const std::string& app_id) = 0;
 
   // Sends a message to a given receiver. Delegate::OnSendFinished will be
   // called asynchronously upon completion.
   // |app_id|: application ID.
   // |receiver_id|: registration ID of the receiver party.
   // |message|: message to be sent.
   virtual void Send(const std::string& app_id,
                     const std::string& receiver_id,
                     const OutgoingMessage& message) = 0;
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_GCM_CLIENT_H_