[GCM] Only allow the senders that the application is currently registered for

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 59 matching lines @@
     MessageData data;
   };
 
   // Message being received from the other party.
   struct GCM_EXPORT IncomingMessage {
     IncomingMessage();
     ~IncomingMessage();
 
     MessageData data;
     std::string collapse_key;
+    std::string sender_id;
   };
 
   // A delegate interface that allows the GCMClient instance to interact with
   // its caller, i.e. notifying asynchronous event.
   class Delegate {
    public:
     // Called when the registration completed successfully or an error occurs.
     // |app_id|: application ID.
     // |registration_id|: non-empty if the registration completed successfully.
     // |result|: the type of the error if an error occured, success otherwise.
@@ skipping 92 matching lines @@
   // |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_