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

extensions/browser/api/declarative/rules_registry.cc

Index: extensions/browser/api/declarative/rules_registry.cc
diff --git a/extensions/browser/api/declarative/rules_registry.cc b/extensions/browser/api/declarative/rules_registry.cc
index 2c1c5d3541eb8c04353d8a41b6ec0611d84e2c38..64c681b41be4124ec00117f12505c60a6b761940 100644
--- a/extensions/browser/api/declarative/rules_registry.cc
+++ b/extensions/browser/api/declarative/rules_registry.cc
@@ -40,13 +40,13 @@ std::vector<linked_ptr<extensions::RulesRegistry::Rule> > RulesFromValue(
     const base::Value* value) {
   std::vector<linked_ptr<extensions::RulesRegistry::Rule> > rules;
 
-  const base::ListValue* list = NULL;
+  const base::ListValue* list = nullptr;
   if (!value || !value->GetAsList(&list))
     return rules;
 
   rules.reserve(list->GetSize());
   for (size_t i = 0; i < list->GetSize(); ++i) {
-    const base::DictionaryValue* dict = NULL;
+    const base::DictionaryValue* dict = nullptr;
     if (!list->GetDictionary(i, &dict))
       continue;
     linked_ptr<extensions::RulesRegistry::Rule> rule(
@@ -80,7 +80,7 @@ RulesRegistry::RulesRegistry(content::BrowserContext* browser_context,
       webview_key_(webview_key),
       ready_(/*signaled=*/!cache_delegate),  // Immediately ready if no cache
                                              // delegate to wait for.
-      weak_ptr_factory_(browser_context_ ? this : NULL),
+      weak_ptr_factory_(browser_context_ ? this : nullptr),
       last_generated_rule_identifier_id_(0) {
   if (cache_delegate) {
     cache_delegate_ = cache_delegate->GetWeakPtr();