buffet: Comments and formating

Renamed local variable.
Added local comment.
Reordered some constants.

BUG=None
TEST=FEATURES=test emerge-gizmo buffet

Change-Id: Ie20e54f4df882f06b8e3912616affe7b50ed7b6d
Reviewed-on: https://chromium-review.googlesource.com/268782
Tested-by: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
diff --git a/buffet/commands/object_schema.cc b/buffet/commands/object_schema.cc
index 96fe952..6838794 100644
--- a/buffet/commands/object_schema.cc
+++ b/buffet/commands/object_schema.cc
@@ -294,7 +294,7 @@
   for (const auto& pair : properties_) {
     auto PropDef = pair.second->ToJson(full_schema, error);
     if (!PropDef)
-      return std::unique_ptr<base::DictionaryValue>();
+      return {};
     value->SetWithoutPathExpansion(pair.first, PropDef.release());
   }
   return value;