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

extensions/common/permissions/permission_message_util.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 "extensions/common/permissions/permission_message_util.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "extensions/common/permissions/permission_message.h"
 #include "extensions/common/permissions/permission_set.h"
@@ skipping 51 matching lines @@
             ? l10n_util::GetStringFUTF16(host_msg_id,
                                          base::UTF8ToUTF16(host.erase(0, 2)))
             : base::UTF8ToUTF16(host));
   }
   DCHECK(host_list.size());
 
   if (host_list.size() < arraysize(kMessagesList)) {
     return PermissionMessage(
         kMessagesList[host_list.size() - 1].first,
         l10n_util::GetStringFUTF16(
-            kMessagesList[host_list.size() - 1].second, host_list, NULL));
+            kMessagesList[host_list.size() - 1].second, host_list, nullptr));
   }
 
   base::string16 details;
   for (size_t i = 0; i < host_list.size(); ++i) {
     if (i > 0)
       details += base::ASCIIToUTF16("\n");
     details += l10n_util::GetStringFUTF16(
         IDS_EXTENSION_PROMPT_WARNING_HOST_LIST_ENTRY, host_list[i]);
   }
   return PermissionMessage(
@@ skipping 53 matching lines @@
   // Build up the final vector by concatenating hosts and RCDs.
   std::set<std::string> distinct_hosts;
   for (HostVector::iterator it = hosts_best_rcd.begin();
        it != hosts_best_rcd.end();
        ++it)
     distinct_hosts.insert(it->first + it->second);
   return distinct_hosts;
 }
 
 }  // namespace permission_message_util