[DevTools] Remove Common.Event.target field.

third_party/WebKit/Source/devtools/front_end/elements/ElementsPanel.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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
@@ skipping 344 matching lines @@
   }
 
   _reset() {
     delete this.currentQuery;
   }
 
   /**
    * @param {!Common.Event} event
    */
   _documentUpdatedEvent(event) {
-    this._documentUpdated(
-        /** @type {!SDK.DOMModel} */ (event.target), /** @type {?SDK.DOMDocument} */ (event.data));
+    var domModel = /** @type {!SDK.DOMModel} */ (event.data);
+    this._documentUpdated(domModel, domModel.existingDocument());
   }
 
   /**
    * @param {!SDK.DOMModel} domModel
    * @param {?SDK.DOMDocument} inspectedRootDocument
    */
   _documentUpdated(domModel, inspectedRootDocument) {
     this._reset();
     this.searchCanceled();
 
@@ skipping 681 matching lines @@
    * @param {!SDK.DOMNode} node
    * @return {?{title: string, color: string}}
    */
   decorate(node) {
     return {
       color: 'orange',
       title: Common.UIString('Element state: %s', ':' + SDK.CSSModel.fromNode(node).pseudoState(node).join(', :'))
     };
   }
 };