[DevTools] Remove Common.Event.target field.

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

 /*
  * Copyright (C) IBM Corp. 2009  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 98 matching lines @@
   }
 
   /**
    * @param {?string} expression
    * @return {!Sources.WatchExpression}
    */
   _createWatchExpression(expression) {
     this._emptyElement.classList.add('hidden');
     var watchExpression = new Sources.WatchExpression(expression, this._expandController, this._linkifier);
     watchExpression.addEventListener(
-        Sources.WatchExpression.Events.ExpressionUpdated, this._watchExpressionUpdated.bind(this));
+        Sources.WatchExpression.Events.ExpressionUpdated, this._watchExpressionUpdated, this);
     this._bodyElement.appendChild(watchExpression.element());
     this._watchExpressions.push(watchExpression);
     return watchExpression;
   }
 
   /**
    * @param {!Common.Event} event
    */
   _watchExpressionUpdated(event) {
-    var watchExpression = /** @type {!Sources.WatchExpression} */ (event.target);
+    var watchExpression = /** @type {!Sources.WatchExpression} */ (event.data);
     if (!watchExpression.expression()) {
       this._watchExpressions.remove(watchExpression);
       this._bodyElement.removeChild(watchExpression.element());
       this._emptyElement.classList.toggle('hidden', !!this._watchExpressions.length);
     }
 
     this._saveExpressions();
   }
 
   /**
@@ skipping 157 matching lines @@
   }
 
   /**
    * @param {?string} newExpression
    */
   _updateExpression(newExpression) {
     if (this._expression)
       this._expandController.stopWatchSectionsWithId(this._expression);
     this._expression = newExpression;
     this.update();
-    this.dispatchEventToListeners(Sources.WatchExpression.Events.ExpressionUpdated);
+    this.dispatchEventToListeners(Sources.WatchExpression.Events.ExpressionUpdated, this);
   }
 
   /**
    * @param {!Event} event
    */
   _deleteWatchExpression(event) {
     event.consume(true);
     this._updateExpression(null);
   }
 
@@ skipping 99 matching lines @@
     InspectorFrontendHost.copyText(this._valueElement.textContent);
   }
 };
 
 Sources.WatchExpression._watchObjectGroupId = 'watch-group';
 
 /** @enum {symbol} */
 Sources.WatchExpression.Events = {
   ExpressionUpdated: Symbol('ExpressionUpdated')
 };