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

chrome/browser/extensions/api/content_settings/content_settings_store.cc

Index: chrome/browser/extensions/api/content_settings/content_settings_store.cc
diff --git a/chrome/browser/extensions/api/content_settings/content_settings_store.cc b/chrome/browser/extensions/api/content_settings/content_settings_store.cc
index 765636dbf9ec3793ae39732d508de8bc37c38e5a..bf120bc5b08a0d9a72f8da0e5119dc42a6e045bf 100644
--- a/chrome/browser/extensions/api/content_settings/content_settings_store.cc
+++ b/chrome/browser/extensions/api/content_settings/content_settings_store.cc
@@ -288,13 +288,12 @@ void ContentSettingsStore::SetExtensionContentSettingFromList(
     const std::string& extension_id,
     const base::ListValue* list,
     ExtensionPrefsScope scope) {
-  for (base::ListValue::const_iterator it = list->begin();
-       it != list->end(); ++it) {
-    if ((*it)->GetType() != base::Value::TYPE_DICTIONARY) {
+  for (const auto& value : *list) {
+    base::DictionaryValue* dict;
+    if (value->GetAsDictionary(&dict)) {

[danakj, 2016/05/24 20:08:34]

do you mean if (!GetAsDictionary) ?

[dcheng, 2016/05/24 20:39:02]

Yes. =X

       NOTREACHED();
       continue;

[danakj, 2016/05/24 20:08:34]

ಠ_ಠ Should either DCHECK or continue not both. I see this is a popular meme with
value iteration.

[dcheng, 2016/05/24 20:39:02]

Yeah, I think I'd rather not change the semantics of existing code if I can
avoid it though.

     }
-    base::DictionaryValue* dict = static_cast<base::DictionaryValue*>(*it);
     std::string primary_pattern_str;
     dict->GetString(keys::kPrimaryPatternKey, &primary_pattern_str);
     ContentSettingsPattern primary_pattern =