Files.app: Reland r261616: Add a test to rename a file.

chrome/browser/resources/file_manager/foreground/js/file_manager.js

Index: chrome/browser/resources/file_manager/foreground/js/file_manager.js
diff --git a/chrome/browser/resources/file_manager/foreground/js/file_manager.js b/chrome/browser/resources/file_manager/foreground/js/file_manager.js
index 7416f7e567f3a85684aa3487cdff2d25624ddc49..6338a156b7b9bd405e6f3cb944f3ebdb4d2ac8d2 100644
--- a/chrome/browser/resources/file_manager/foreground/js/file_manager.js
+++ b/chrome/browser/resources/file_manager/foreground/js/file_manager.js
@@ -2480,8 +2480,8 @@ var BOTTOM_MARGIN_FOR_PREVIEW_PANEL_PX = 52;
       return;
     }
 
-    var nameNode = this.findListItemForNode_(this.renameInput_).
-                   querySelector('.filename-label');
+    var renamedItemElement = this.findListItemForNode_(this.renameInput_);
+    var nameNode = renamedItemElement.querySelector('.filename-label');
 
     input.validation_ = true;
     var validationDone = function(valid) {
@@ -2498,15 +2498,19 @@ var BOTTOM_MARGIN_FOR_PREVIEW_PANEL_PX = 52;
       // Optimistically apply new name immediately to avoid flickering in
       // case of success.
       nameNode.textContent = newName;
+      // Add a marker of the provisional change for test cases.
+      renamedItemElement.classList.add('provisional');
 
       util.rename(
           entry, newName,
           function(newEntry) {
             this.directoryModel_.onRenameEntry(entry, newEntry);
+            renamedItemElement.classList.remove('provisional');
           }.bind(this),
           function(error) {
             // Write back to the old name.
             nameNode.textContent = entry.name;
+            renamedItemElement.classList.remove('provisional');
 
             // Show error dialog.
             var message;