replace NULL->nullptr in src/remoting.

remoting/protocol/host_event_dispatcher.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 "remoting/protocol/host_event_dispatcher.h"
 
 #include "base/callback_helpers.h"
 #include "net/socket/stream_socket.h"
 #include "remoting/base/constants.h"
 #include "remoting/proto/event.pb.h"
 #include "remoting/proto/internal.pb.h"
 #include "remoting/protocol/input_stub.h"
 
 namespace remoting {
 namespace protocol {
 
 HostEventDispatcher::HostEventDispatcher()
     : ChannelDispatcherBase(kEventChannelName),
-      input_stub_(NULL) {
+      input_stub_(nullptr) {
 }
 
 HostEventDispatcher::~HostEventDispatcher() {
 }
 
 void HostEventDispatcher::OnInitialized() {
   reader_.Init(channel(), base::Bind(
       &HostEventDispatcher::OnMessageReceived, base::Unretained(this)));
 }
 
@@ skipping 22 matching lines @@
     }
   } else if (message->has_mouse_event()) {
     input_stub_->InjectMouseEvent(message->mouse_event());
   } else {
     LOG(WARNING) << "Unknown event message received.";
   }
 }
 
 }  // namespace protocol
 }  // namespace remoting