Revert of Change base::Value::ListStorage to std::vector<base::Value>

ui/display/manager/json_converter.cc

Index: ui/display/manager/json_converter.cc
diff --git a/ui/display/manager/json_converter.cc b/ui/display/manager/json_converter.cc
index 2520d1d68388862b9b950127a42bad2380da0f4d..213f7e404932a4bfa50806cc016557b52ab4e41d 100644
--- a/ui/display/manager/json_converter.cc
+++ b/ui/display/manager/json_converter.cc
@@ -125,7 +125,7 @@
   output->reserve(list->GetSize());
   for (const auto& list_item : *list) {
     const base::DictionaryValue* item_values = nullptr;
-    if (!list_item.GetAsDictionary(&item_values))
+    if (!list_item->GetAsDictionary(&item_values))
       return false;
 
     DisplayPlacement item;