[Signin] Remove a reference to an obsolete bug.

chrome/browser/services/gcm/gcm_service.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 CHROME_BROWSER_SERVICES_GCM_GCM_SERVICE_H_
 #define CHROME_BROWSER_SERVICES_GCM_GCM_SERVICE_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 54 matching lines @@
 
   // Registers |sender_id| for an app. A registration ID will be returned by
   // the GCM server.
   // |app_id|: application ID.
   // |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.
   // |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,
-                        RegisterCallback callback);
+                        const RegisterCallback& callback);
 
   // Unregisters an app from using GCM.
   // |app_id|: application ID.
   // |callback|: to be called once the asynchronous operation is done.
   virtual void Unregister(const std::string& app_id,
-                          UnregisterCallback callback);
+                          const UnregisterCallback& callback);
 
   // Sends a message to a given receiver.
   // |app_id|: application ID.
   // |receiver_id|: registration ID of the receiver party.
   // |message|: message to be sent.
   // |callback|: to be called once the asynchronous operation is done.
   virtual void Send(const std::string& app_id,
                     const std::string& receiver_id,
                     const GCMClient::OutgoingMessage& message,
-                    SendCallback callback);
+                    const SendCallback& callback);
 
   // For testing purpose.
   GCMClient* GetGCMClientForTesting() const;
 
   // Returns true if the service was started.
   bool IsStarted() const;
 
   // Returns true if the gcm client is ready.
   bool IsGCMClientReady() const;
 
   // Get GCM client internal states and statistics.
   // If clear_logs is true then activity logs will be cleared before the stats
   // are returned.
-  void GetGCMStatistics(GetGCMStatisticsCallback callback, bool clear_logs);
+  void GetGCMStatistics(const GetGCMStatisticsCallback& callback,
+                        bool clear_logs);
 
   // Enables/disables GCM activity recording, and then returns the stats.
-  void SetGCMRecording(GetGCMStatisticsCallback callback, bool recording);
+  void SetGCMRecording(const GetGCMStatisticsCallback& callback,
+                       bool recording);
 
   // IdentityProvider::Observer:
   virtual void OnActiveAccountLogin() OVERRIDE;
   virtual void OnActiveAccountLogout() OVERRIDE;
 
  protected:
   virtual bool ShouldStartAutomatically() const = 0;
 
   virtual base::FilePath GetStorePath() const = 0;
 
@@ skipping 89 matching lines @@
 
   // Used to pass a weak pointer to the IO worker.
   base::WeakPtrFactory<GCMService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GCMService);
 };
 
 }  // namespace gcm
 
 #endif  // CHROME_BROWSER_SERVICES_GCM_GCM_SERVICE_H_