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

extensions/browser/api/storage/settings_storage_quota_enforcer.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/browser/api/storage/settings_storage_quota_enforcer.h"
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 39 matching lines @@
 void Free(
     size_t* used_total,
     std::map<std::string, size_t>* used_per_setting,
     const std::string& key) {
   *used_total -= (*used_per_setting)[key];
   used_per_setting->erase(key);
 }
 
 scoped_ptr<ValueStore::Error> QuotaExceededError(Resource resource,
                                                  scoped_ptr<std::string> key) {
-  const char* name = NULL;
+  const char* name = nullptr;
   // TODO(kalman): These hisograms are both silly and untracked. Fix.
   switch (resource) {
     case QUOTA_BYTES:
       name = "QUOTA_BYTES";
       UMA_HISTOGRAM_COUNTS_100(
           "Extensions.SettingsQuotaExceeded.TotalBytes", 1);
       break;
     case QUOTA_BYTES_PER_ITEM:
       name = "QUOTA_BYTES_PER_ITEM";
       UMA_HISTOGRAM_COUNTS_100(
@@ skipping 193 matching lines @@
   }
 
   for (base::DictionaryValue::Iterator it(maybe_settings->settings());
        !it.IsAtEnd();
        it.Advance()) {
     Allocate(it.key(), it.value(), &used_total_, &used_per_setting_);
   }
 }
 
 }  // namespace extensions