[Sync] Replacing NULL with nullptr in code and null in comments for components/sync/

components/sync/engine_impl/net/server_connection_manager.h

 // Copyright 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 COMPONENTS_SYNC_ENGINE_IMPL_NET_SERVER_CONNECTION_MANAGER_H_
 #define COMPONENTS_SYNC_ENGINE_IMPL_NET_SERVER_CONNECTION_MANAGER_H_
 
 #include <stdint.h>
 
 #include <iosfwd>
@@ skipping 212 matching lines @@
                                 const std::string& path,
                                 const std::string& auth_token);
 
   // An internal helper to clear our auth_token_ and cache the old version
   // in |previously_invalidated_token_| to shelter us from retrying with a
   // known bad token.
   void InvalidateAndClearAuthToken();
 
   // Helper to check terminated flags and build a Connection object, installing
   // it as the |active_connection_|.  If this ServerConnectionManager has been
-  // terminated, this will return NULL.
+  // terminated, this will return null.
   Connection* MakeActiveConnection();
 
   // Called by Connection objects as they are destroyed to allow the
   // ServerConnectionManager to cleanup active connections.
   void OnConnectionDestroyed(Connection* connection);
 
   // The sync_server_ is the server that requests will be made to.
   std::string sync_server_;
 
   // The sync_server_port_ is the port that HTTP requests will be made on.
@@ skipping 56 matching lines @@
   bool signal_handler_registered_;
 
   DISALLOW_COPY_AND_ASSIGN(ServerConnectionManager);
 };
 
 std::ostream& operator<<(std::ostream& s, const struct HttpResponse& hr);
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_IMPL_NET_SERVER_CONNECTION_MANAGER_H_