Use std::unique_ptr for base::DictionaryValue and base::ListValue's internal store.

chromeos/network/onc/onc_mapper.cc

Index: chromeos/network/onc/onc_mapper.cc
diff --git a/chromeos/network/onc/onc_mapper.cc b/chromeos/network/onc/onc_mapper.cc
index d5df15ef23c4a9465fa590be0c77f4260e306d2e..1da58015c39f6b44354f8e4ea7fbb14e44da0210 100644
--- a/chromeos/network/onc/onc_mapper.cc
+++ b/chromeos/network/onc/onc_mapper.cc
@@ -116,10 +116,7 @@ std::unique_ptr<base::ListValue> Mapper::MapArray(
 
   std::unique_ptr<base::ListValue> result_array(new base::ListValue);
   int original_index = 0;
-  for (base::ListValue::const_iterator it = onc_array.begin();
-       it != onc_array.end(); ++it, ++original_index) {
-    const base::Value* entry = *it;
-
+  for (const auto& entry : onc_array) {
     std::unique_ptr<base::Value> result_entry;
     result_entry = MapEntry(original_index,
                             *array_signature.onc_array_entry_signature,