Files.app: Update metadata by using new metadata cache event.

ui/file_manager/file_manager/foreground/js/directory_model.js

Index: ui/file_manager/file_manager/foreground/js/directory_model.js
diff --git a/ui/file_manager/file_manager/foreground/js/directory_model.js b/ui/file_manager/file_manager/foreground/js/directory_model.js
index 5b3c6476660e9f6747673e2cc25f64b976988420..da4a8ace44e3af4db5444dd090f2c13cddab1912 100644
--- a/ui/file_manager/file_manager/foreground/js/directory_model.js
+++ b/ui/file_manager/file_manager/foreground/js/directory_model.js
@@ -122,6 +122,14 @@ DirectoryModel.prototype.getCurrentRootType = function() {
 };
 
 /**
+ * Metadata property names that are expected to be Prefetched.
+ * @return {!Array<string>}
+ */
+DirectoryModel.prototype.getPrefetchPropertyNames = function() {
+  return this.currentFileListContext_.prefetchPropertyNames;
+};
+
+/**
  * @return {boolean} True if the current directory is read only. If there is
  *     no entry set, then returns true.
  */