[DevTools] Remove removeAllListeners method.

third_party/WebKit/Source/devtools/front_end/common/Object.js

 /*
  * Copyright (C) 2008 Apple 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 51 matching lines @@
       if (listeners[i].listener === listener && listeners[i].thisObject === thisObject)
         listeners.splice(i--, 1);
     }
 
     if (!listeners.length)
       this._listeners.delete(eventType);
   }
 
   /**
    * @override
-   */
-  removeAllListeners() {
-    delete this._listeners;
-  }
-
-  /**
-   * @override
    * @param {symbol} eventType
    * @return {boolean}
    */
   hasEventListeners(eventType) {
     return this._listeners && this._listeners.has(eventType);
   }
 
   /**
    * @override
    * @param {symbol} eventType
@@ skipping 48 matching lines @@
    */
   addEventListener(eventType, listener, thisObject) {},
 
   /**
    * @param {symbol} eventType
    * @param {function(!Common.Event)} listener
    * @param {!Object=} thisObject
    */
   removeEventListener(eventType, listener, thisObject) {},
 
-  removeAllListeners() {},
-
   /**
    * @param {symbol} eventType
    * @return {boolean}
    */
   hasEventListeners(eventType) {},
 
   /**
    * @param {symbol} eventType
    * @param {*=} eventData
    */
@@ skipping 10 matching lines @@
    * @param {(!Object|undefined)} receiver
    * @param {function(?):?} method
    */
   constructor(eventTarget, eventType, receiver, method) {
     this.eventTarget = eventTarget;
     this.eventType = eventType;
     this.receiver = receiver;
     this.method = method;
   }
 };