Replace NULL with nullptr or null in webrtc/base/.

webrtc/base/unittest_main.cc

 /*
  *  Copyright 2007 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 //
@@ skipping 48 matching lines @@
     *retval = 0;
     return TRUE;
   }
 }
 #endif  // WEBRTC_WIN
 
 int main(int argc, char** argv) {
   testing::InitGoogleTest(&argc, argv);
   rtc::FlagList::SetFlagsFromCommandLine(&argc, argv, false);
   if (FLAG_help) {
-    rtc::FlagList::Print(NULL, false);
+    rtc::FlagList::Print(nullptr, false);
     return 0;
   }
 
   webrtc::test::SetExecutablePath(argv[0]);
   webrtc::test::InitFieldTrialsFromString(FLAG_force_fieldtrials);
 
 #if defined(WEBRTC_WIN)
   if (!FLAG_default_error_handlers) {
     // Make sure any errors don't throw dialogs hanging the test run.
     _set_invalid_parameter_handler(TestInvalidParameterHandler);
@@ skipping 35 matching lines @@
 
 #if defined(WEBRTC_WIN)
   // Unhook crt function so that we don't ever log after statics have been
   // uninitialized.
   if (!FLAG_default_error_handlers)
     _CrtSetReportHook2(_CRT_RPTHOOK_REMOVE, TestCrtReportHandler);
 #endif
 
   return res;
 }