Adds a comment explaining why we are forcing materialization of the R…

…ecordArray returned by store.query

tests/dummy/app/routes/query/route.js

@@ -27,6 +27,10 @@ export default Route.extend({
     let token = heimdall.start('ember-data');
     return this.get('store').query(modelName, params)
       .then((records) => {
+        // RecordArray lazily materializes the records
+        // We call toArray() to force materialization for benchmarking
+        // otherwise we would need to consume the RecordArray in our UI
+        // and clutter our benchmarks and make it harder to time.
         records.toArray();
         heimdall.stop(token);
         window.result = heimdall.toString();