[filebrowser] In Gallery, do not allow file names starting with dot.

chrome/browser/resources/file_manager/js/image_editor/gallery.js

 // Copyright (c) 2012 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.
 
 /*
  * Base class that Ribbon uses to display photos.
  */
 
 function RibbonClient() {}
 
@@ skipping 318 matching lines @@
   this.initiateFading_();
 };
 
 Gallery.prototype.onFilenameEditKeydown_ = function() {
   switch (event.keyCode) {
     case 27:  // Escape
       this.filenameEdit_.blur();
       break;
 
     case 13:  // Enter
+      if (this.filenameEdit_.value && this.filenameEdit_.value[0] == '.') {
+        this.editor_.getPrompt().show('file_hidden_name', 5000);
+        break;
+      }
       if (this.filenameEdit_.value) {
         this.renameItem_(this.ribbon_.getSelectedItem(),
             this.filenameEdit_.value);
         this.filenameEdit_.blur();
       }
       break;
   }
   event.stopPropagation();
 };
 
@@ skipping 860 matching lines @@
 ShareMode.prototype.setUp = function() {
   ImageEditor.Mode.prototype.setUp.apply(this, arguments);
   ImageUtil.setAttribute(this.menu_, 'hidden', false);
   ImageUtil.setAttribute(this.button_, 'pressed', false);
 };
 
 ShareMode.prototype.cleanUpUI = function() {
   ImageEditor.Mode.prototype.cleanUpUI.apply(this, arguments);
   ImageUtil.setAttribute(this.menu_, 'hidden', true);
 };