Run clang-modernize -use-nullptr over src/extensions/.

extensions/test/extensions_unittests_main.cc

 // 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 "base/base_paths.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/path_service.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "content/public/common/content_client.h"
@@ skipping 70 matching lines @@
   PathService::Get(base::DIR_MODULE, &extensions_shell_and_test_pak_path);
   ui::ResourceBundle::InitSharedInstanceWithPakPath(
       extensions_shell_and_test_pak_path.AppendASCII(
           "extensions_shell_and_test.pak"));
 
   client_.reset(new extensions::TestExtensionsClient());
   extensions::ExtensionsClient::Set(client_.get());
 }
 
 void ExtensionsTestSuite::Shutdown() {
-  extensions::ExtensionsClient::Set(NULL);
+  extensions::ExtensionsClient::Set(nullptr);
   client_.reset();
 
   ui::ResourceBundle::CleanupSharedInstance();
   content::ContentTestSuiteBase::Shutdown();
 }
 
 }  // namespace
 
 int main(int argc, char** argv) {
   content::UnitTestTestSuite test_suite(new ExtensionsTestSuite(argc, argv));
 
   mojo::embedder::test::InitWithSimplePlatformSupport();
   return base::LaunchUnitTests(argc,
                                argv,
                                base::Bind(&content::UnitTestTestSuite::Run,
                                           base::Unretained(&test_suite)));
 }