chromeos: Convert D-Bus client classes' callback arguments to const reference

chromeos/dbus/cashew_client.cc

 // Copyright (c) 2012 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.
 
 #include "chromeos/dbus/cashew_client.h"
 
 #include "base/bind.h"
 #include "base/values.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
@@ skipping 23 matching lines @@
         cashew::kCashewServiceInterface,
         cashew::kMonitorDataPlanUpdate,
         base::Bind(&CashewClientImpl::OnDataPlansUpdate,
                    weak_ptr_factory_.GetWeakPtr()),
         base::Bind(&CashewClientImpl::OnSignalConnected,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
   // CashewClient override.
   virtual void SetDataPlansUpdateHandler(
-      DataPlansUpdateHandler handler) OVERRIDE {
+      const DataPlansUpdateHandler& handler) OVERRIDE {
     data_plans_update_handler_ = handler;
   }
 
   // CashewClient override.
   virtual void ResetDataPlansUpdateHandler() OVERRIDE {
     data_plans_update_handler_.Reset();
   }
 
   // CashewClient override.
   virtual void RequestDataPlansUpdate() OVERRIDE {
@@ skipping 39 matching lines @@
 
 // A stub implementaion of CashewClient.
 class CashewClientStubImpl : public CashewClient {
  public:
   CashewClientStubImpl() {}
 
   virtual ~CashewClientStubImpl() {}
 
   // CashewClient override.
   virtual void SetDataPlansUpdateHandler(
-      DataPlansUpdateHandler handler) OVERRIDE {}
+      const DataPlansUpdateHandler& handler) OVERRIDE {}
 
   // CashewClient override.
   virtual void ResetDataPlansUpdateHandler() OVERRIDE {}
 
   // CashewClient override.
   virtual void RequestDataPlansUpdate() OVERRIDE {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CashewClientStubImpl);
 };
@@ skipping 10 matching lines @@
 // static
 CashewClient* CashewClient::Create(DBusClientImplementationType type,
                                    dbus::Bus* bus) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
     return new CashewClientImpl(bus);
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new CashewClientStubImpl();
 }
 
 }  // namespace chromeos