[filebrowser] Fix copying selected file name to input field.

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

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Setting the src of an img to an empty string can crash the browser, so we
 // use an empty 1x1 gif instead.
 const EMPTY_IMAGE_URI = 'data:image/gif;base64,'
         + 'R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw%3D%3D';
 
 var g_slideshow_data = null;
@@ skipping 2500 matching lines @@
   FileManager.prototype.onSelectionChanged_ = function(event) {
     this.summarizeSelection_();
 
     if (this.dialogType_ == FileManager.DialogType.SELECT_SAVEAS_FILE) {
       // If this is a save-as dialog, copy the selected file into the filename
       // input text box.
 
       if (this.selection &&
           this.selection.totalCount == 1 &&
           this.selection.entries[0].isFile)
-        this.filenameInput_.value = leadEntry.name;
+        this.filenameInput_.value = this.getLeadEntry().name;
     }
 
     this.updateOkButton_();
 
     var self = this;
     setTimeout(function() { self.onSelectionChangeComplete_(event) }, 0);
   };
 
   /**
    * Handle selection change related tasks that won't run properly during
@@ skipping 858 matching lines @@
 
     if (msg) {
       console.log('no no no');
       this.alert.show(msg, onAccept);
       return false;
     }
 
     return true;
   };
 })();