[DevTools] Remove Common.Event.target field.

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

 // Copyright 2014 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.
 /**
  * @implements {Sources.TabbedEditorContainerDelegate}
  * @implements {UI.Searchable}
  * @implements {UI.Replaceable}
  * @unrestricted
  */
 Sources.SourcesView = class extends UI.VBox {
@@ skipping 465 matching lines @@
     this._searchableView.refreshSearch();
     this._updateScriptViewToolbarItems();
 
     this.dispatchEventToListeners(Sources.SourcesView.Events.EditorSelected, this._editorContainer.currentFile());
   }
 
   /**
    * @param {!Common.Event} event
    */
   _uiSourceCodeTitleChanged(event) {
-    this._recreateSourceFrameIfNeeded(/** @type {!Workspace.UISourceCode} */ (event.target));
+    this._recreateSourceFrameIfNeeded(/** @type {!Workspace.UISourceCode} */ (event.data));
   }
 
   /**
    * @override
    */
   searchCanceled() {
     if (this._searchView)
       this._searchView.searchCanceled();
 
     delete this._searchView;
@@ skipping 281 matching lines @@
    * @return {boolean}
    */
   handleAction(context, actionId) {
     var sourcesView = UI.context.flavor(Sources.SourcesView);
     if (!sourcesView)
       return false;
     sourcesView._editorContainer.closeAllFiles();
     return true;
   }
 };