replace NULL->nullptr in src/remoting.

remoting/host/setup/daemon_installer_win.h

 // 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.
 
 #ifndef REMOTING_HOST_DAEMON_INSTALLER_WIN_H_
 #define REMOTING_HOST_DAEMON_INSTALLER_WIN_H_
 
 #include <objbase.h>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace remoting {
 
 class DaemonInstallerWin {
  public:
   typedef base::Callback<void (HRESULT result)> CompletionCallback;
 
   virtual ~DaemonInstallerWin();
 
   // Initiates download and installation of the Chromoting Host.
   virtual void Install() = 0;
 
   // Creates an instance of the Chromoting Host installer passing the completion
   // callback to be called when the installation finishes. In case of an error
-  // returns NULL and passed the error code to |done|.
+  // returns nullptr and passed the error code to |done|.
   static scoped_ptr<DaemonInstallerWin> Create(HWND window_handle,
                                                CompletionCallback done);
 
  protected:
   DaemonInstallerWin(const CompletionCallback& done);
 
   // Invokes the completion callback to report the installation result.
   void Done(HRESULT result);
 
  private:
   // The completion callback that should be called to report the installation
   // result.
   CompletionCallback done_;
 
   DISALLOW_COPY_AND_ASSIGN(DaemonInstallerWin);
 };
 
 // Returns the first top-level (i.e. WS_OVERLAPPED or WS_POPUP) window in
 // the chain of parents of |window|. Returns |window| if it represents
-// a top-level window. Returns NULL when |window| is NULL.
+// a top-level window. Returns nullptr when |window| is nullptr.
 HWND GetTopLevelWindow(HWND window);
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_DAEMON_INSTALLER_WIN_H_