[DevTools] Remove Common.Event.target field.

third_party/WebKit/Source/devtools/front_end/emulation/TouchModel.js

 // Copyright 2016 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 {SDK.TargetManager.Observer}
  * @unrestricted
  */
 Emulation.MultitargetTouchModel = class {
   constructor() {
     this._touchEnabled = false;
@@ skipping 89 matching lines @@
       (target[symbol] || {}).scriptId = error ? '' : scriptId;
     }
 
     target.emulationAgent().setTouchEmulationEnabled(current.enabled, current.configuration);
   }
 
   /**
    * @param {!Common.Event} event
    */
   _inspectModeToggled(event) {
-    var domModel = /** @type {!SDK.DOMModel} */ (event.target);
+    var domModel = /** @type {!SDK.DOMModel} */ (event.data);
     this._applyToTarget(domModel.target());
   }
 
   /**
    * @override
    * @param {!SDK.Target} target
    */
   targetAdded(target) {
     var domModel = SDK.DOMModel.fromTarget(target);
     if (domModel)
       domModel.addEventListener(SDK.DOMModel.Events.InspectModeWillBeToggled, this._inspectModeToggled, this);
     this._applyToTarget(target);
   }
 
   /**
    * @override
    * @param {!SDK.Target} target
    */
   targetRemoved(target) {
     var domModel = SDK.DOMModel.fromTarget(target);
     if (domModel)
       domModel.removeEventListener(SDK.DOMModel.Events.InspectModeWillBeToggled, this._inspectModeToggled, this);
   }
 };
 
 Emulation.MultitargetTouchModel._symbol = Symbol('MultitargetTouchModel.symbol');
 
 /** @type {?Emulation.MultitargetTouchModel} */
 Emulation.MultitargetTouchModel._instance = null;