Revert of [DevTools] Remove methods on Common.Event.

third_party/WebKit/Source/devtools/front_end/sources/SourcesNavigator.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 128 matching lines @@
 
 /**
  * @unrestricted
  */
 Sources.FilesNavigatorView = class extends Sources.NavigatorView {
   constructor() {
     super();
     var toolbar = new UI.Toolbar('navigator-toolbar');
     var title = Common.UIString('Add folder to workspace');
     var addButton = new UI.ToolbarButton(title, 'largeicon-add', title);
-    addButton.addEventListener(
-        UI.ToolbarButton.Events.Click, () => Workspace.isolatedFileSystemManager.addFileSystem());
+    addButton.addEventListener('click', () => Workspace.isolatedFileSystemManager.addFileSystem());
     toolbar.appendToolbarItem(addButton);
     this.element.insertBefore(toolbar.element, this.element.firstChild);
   }
 
   /**
    * @override
    * @param {!Workspace.UISourceCode} uiSourceCode
    * @return {boolean}
    */
   accept(uiSourceCode) {
@@ skipping 30 matching lines @@
 };
 
 /**
  * @unrestricted
  */
 Sources.SnippetsNavigatorView = class extends Sources.NavigatorView {
   constructor() {
     super();
     var toolbar = new UI.Toolbar('navigator-toolbar');
     var newButton = new UI.ToolbarButton('', 'largeicon-add', Common.UIString('New Snippet'));
-    newButton.addEventListener(UI.ToolbarButton.Events.Click, this._handleCreateSnippet.bind(this));
+    newButton.addEventListener('click', this._handleCreateSnippet.bind(this));
     toolbar.appendToolbarItem(newButton);
     this.element.insertBefore(toolbar.element, this.element.firstChild);
   }
 
   /**
    * @override
    * @param {!Workspace.UISourceCode} uiSourceCode
    * @return {boolean}
    */
   accept(uiSourceCode) {
@@ skipping 59 matching lines @@
     this.create(Snippets.scriptSnippetModel.project(), '');
   }
 
   /**
    * @override
    */
   sourceDeleted(uiSourceCode) {
     this._handleRemoveSnippet(uiSourceCode);
   }
 };