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

chrome/browser/services/gcm/gcm_profile_service.h

Index: chrome/browser/services/gcm/gcm_profile_service.h
diff --git a/chrome/browser/services/gcm/gcm_profile_service.h b/chrome/browser/services/gcm/gcm_profile_service.h
index a516d710c221b435ef35a4b3d2460d3a87abcc92..99d7d4219361a40b6880b705e96b2f86067d020a 100644
--- a/chrome/browser/services/gcm/gcm_profile_service.h
+++ b/chrome/browser/services/gcm/gcm_profile_service.h
@@ -83,7 +83,7 @@ class GCMProfileService : public BrowserContextKeyedService,
   //               Google API Console.
   // |callback|: to be called once the asynchronous operation is done.
   virtual void Register(const std::string& app_id,
-                        const std::vector<std::string>& sender_ids,
+                        const std::string& sender_id,
                         const std::string& cert,
                         RegisterCallback callback);
 
@@ -115,7 +115,7 @@ class GCMProfileService : public BrowserContextKeyedService,
     ~RegistrationInfo();
     bool IsValid() const;
 
-    std::vector<std::string> sender_ids;
+    std::string sender_id;
     std::string registration_id;
   };
 
@@ -143,7 +143,7 @@ class GCMProfileService : public BrowserContextKeyedService,
   void Unregister(const std::string& app_id);
 
   void DoRegister(const std::string& app_id,
-                  const std::vector<std::string>& sender_ids,
+                  const std::string& sender_id,
                   const std::string& cert);
   void DoSend(const std::string& app_id,
               const std::string& receiver_id,