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

extensions/common/api/declarative/declarative_manifest_data.cc

Index: extensions/common/api/declarative/declarative_manifest_data.cc
diff --git a/extensions/common/api/declarative/declarative_manifest_data.cc b/extensions/common/api/declarative/declarative_manifest_data.cc
index 310113098de1cc501a8bf0177c0d95d845e7b9f8..13bfdcc56f11a5344a8e48c5f6b1be55650a4d46 100644
--- a/extensions/common/api/declarative/declarative_manifest_data.cc
+++ b/extensions/common/api/declarative/declarative_manifest_data.cc
@@ -129,9 +129,9 @@
 
   for (const auto& element : *list) {
     const base::DictionaryValue* dict = nullptr;
-    if (!element.GetAsDictionary(&dict)) {
+    if (!element->GetAsDictionary(&dict)) {
       error_builder.Append("expected dictionary, got %s",
-                           base::Value::GetTypeName(element.GetType()));
+                           base::Value::GetTypeName(element->GetType()));
       return std::unique_ptr<DeclarativeManifestData>();
     }
     std::string event;