replace NULL->nullptr in src/remoting.

remoting/host/desktop_session_agent.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/host/desktop_session_agent.h"
 
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/memory/shared_memory.h"
 #include "ipc/ipc_channel_proxy.h"
@@ skipping 353 matching lines @@
     LOG(ERROR) << "Failed to serialize AudioPacket.";
     return;
   }
 
   SendToNetwork(new ChromotingDesktopNetworkMsg_AudioPacket(serialized_packet));
 }
 
 bool DesktopSessionAgent::Start(const base::WeakPtr<Delegate>& delegate,
                                 IPC::PlatformFileForTransit* desktop_pipe_out) {
   DCHECK(caller_task_runner_->BelongsToCurrentThread());
-  DCHECK(delegate_.get() == NULL);
+  DCHECK(delegate_.get() == nullptr);
 
   delegate_ = delegate;
 
   // Create an IPC channel to communicate with the network process.
   bool result = CreateConnectedIpcChannel(io_task_runner_,
                                           this,
                                           &desktop_pipe_,
                                           &network_channel_);
   base::PlatformFile raw_desktop_pipe = desktop_pipe_.GetPlatformFile();
 #if defined(OS_WIN)
@@ skipping 194 matching lines @@
 void DesktopSessionAgent::OnSharedBufferDeleted(int id) {
   DCHECK(video_capture_task_runner_->BelongsToCurrentThread());
   DCHECK(id != 0);
 
   shared_buffers_--;
   DCHECK_GE(shared_buffers_, 0);
   SendToNetwork(new ChromotingDesktopNetworkMsg_ReleaseSharedBuffer(id));
 }
 
 }  // namespace remoting