replace NULL->nullptr in src/remoting.

remoting/host/cast_extension_session.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 REMOTING_HOST_CAST_EXTENSION_SESSION_H_
 #define REMOTING_HOST_CAST_EXTENSION_SESSION_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 137 matching lines @@
   //      "candidate" : "...",
   //      "sdpMid" : "...",
   //      "sdpMLineIndex" : "..."
   //    }
   // }
   //
   bool SendMessageToClient(const std::string& subject, const std::string& data);
 
   // Creates the jingle wrapper for the current thread, sets send to allowed,
   // and saves a pointer to the relevant thread pointer in ptr. If |event|
-  // is not NULL, signals the event on completion.
+  // is not nullptr, signals the event on completion.
   void EnsureTaskAndSetSend(rtc::Thread** ptr,
-                            base::WaitableEvent* event = NULL);
+                            base::WaitableEvent* event = nullptr);
 
   // Wraps each task runner in JingleThreadWrapper using EnsureTaskAndSetSend(),
   // returning true if successful. Wrapping the task runners allows them to be
   // shared with and used by the (about to be created) PeerConnectionFactory.
   bool WrapTasksAndSave();
 
   // Initializes PeerConnectionFactory and PeerConnection and sends a "ready"
   // message to client. Returns true if these steps are performed successfully.
   bool InitializePeerConnection();
 
@@ skipping 61 matching lines @@
 
   // Worker thread that is wrapped to create |worker_thread_wrapper_|.
   base::Thread worker_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(CastExtensionSession);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_CAST_EXTENSION_SESSION_H_