Populate volume items without resolving their display roots.

ui/file_manager/file_manager/foreground/js/navigation_list_model.js

Index: ui/file_manager/file_manager/foreground/js/navigation_list_model.js
diff --git a/ui/file_manager/file_manager/foreground/js/navigation_list_model.js b/ui/file_manager/file_manager/foreground/js/navigation_list_model.js
index 77e4f29c2dec7e2ab8c888ad3e9102f854caf86a..33c68809f005c030fcc9c10f2449b71a82d0c0d2 100644
--- a/ui/file_manager/file_manager/foreground/js/navigation_list_model.js
+++ b/ui/file_manager/file_manager/foreground/js/navigation_list_model.js
@@ -18,6 +18,22 @@ NavigationModelItem.prototype = {
 };
 
 /**
+ * Check whether given two model items are same.
+ * @param {NavigationModelItem} item1 The first item to be compared.
+ * @param {NavigationModelItem} item2 The second item to be compared.
+ * @return {boolean} True if given two model items are same.
+ */
+NavigationModelItem.isSame = function(item1, item2) {
+  if (item1.isVolume != item2.isVolume)
+    return false;
+
+  if (item1.isVolume)
+    return item1.volumeInfo === item2.volumeInfo;
+  else
+    return util.isSameEntry(item1.entry, item2.entry);
+};
+
+/**
  * Item of NavigationListModel for shortcuts.
  *
  * @param {string} label Label.