replace NULL->nullptr in src/remoting.

remoting/signaling/server_log_entry_unittest.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.
 
 #include <map>
 #include <set>
 #include <string>
 
 namespace buzz {
 class XmlElement;
 }  // namespace buzz
 
 namespace remoting {
 
 extern const char kJabberClientNamespace[];
 extern const char kChromotingNamespace[];
 
 // Verifies that |stanza| contains a <log> element and returns it. Otherwise
-// returns NULL and records a test failure.
+// returns nullptr and records a test failure.
 buzz::XmlElement* GetLogElementFromStanza(buzz::XmlElement* stanza);
 
 // Verifies that |stanza| contains only 1 log entry, and returns the <entry>
-// element. Otherwise returns NULL and records a test failure.
+// element. Otherwise returns nullptr and records a test failure.
 buzz::XmlElement* GetSingleLogEntryFromStanza(buzz::XmlElement* stanza);
 
 // Verifies a logging stanza.
 // |keyValuePairs| lists the keys that must have specified values, and |keys|
 // lists the keys that must be present, but may have arbitrary values.
 // There must be no other keys.
 bool VerifyStanza(
     const std::map<std::string, std::string>& key_value_pairs,
     const std::set<std::string> keys,
     const buzz::XmlElement* elem,
     std::string* error);
 
 }  // namespace remoting