Revert of [DevTools] Remove methods on Common.Event.

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 69 matching lines @@
    * @return {boolean}
    */
   hasEventListeners(eventType) {
     return this._listeners && this._listeners.has(eventType);
   }
 
   /**
    * @override
    * @param {symbol} eventType
    * @param {*=} eventData
+   * @return {boolean}
    */
   dispatchEventToListeners(eventType, eventData) {
     if (!this._listeners || !this._listeners.has(eventType))
-      return;
+      return false;
 
-    var event = new Common.Event(this, eventData);
+    var event = new Common.Event(this, eventType, eventData);
     var listeners = this._listeners.get(eventType).slice(0);
-    for (var i = 0; i < listeners.length; ++i)
+    for (var i = 0; i < listeners.length; ++i) {
       listeners[i].listener.call(listeners[i].thisObject, event);
+      if (event._stoppedPropagation)
+        break;
+    }
+
+    return event.defaultPrevented;
   }
 };
 
 /**
  * @unrestricted
  */
 Common.Event = class {
   /**
    * @param {!Common.EventTarget} target
+   * @param {symbol} type
    * @param {*=} data
    */
-  constructor(target, data) {
+  constructor(target, type, data) {
     this.target = target;
+    this.type = type;
     this.data = data;
+    this.defaultPrevented = false;
+    this._stoppedPropagation = false;
+  }
+
+  stopPropagation() {
+    this._stoppedPropagation = true;
+  }
+
+  preventDefault() {
+    this.defaultPrevented = true;
+  }
+
+  /**
+   * @param {boolean=} preventDefault
+   */
+  consume(preventDefault) {
+    this.stopPropagation();
+    if (preventDefault)
+      this.preventDefault();
   }
 };
 
 /**
  * @interface
  */
 Common.EventTarget = function() {};
 
 /**
  * @param {!Array<!Common.EventTarget.EventDescriptor>} eventList
@@ skipping 27 matching lines @@
 
   /**
    * @param {symbol} eventType
    * @return {boolean}
    */
   hasEventListeners(eventType) {},
 
   /**
    * @param {symbol} eventType
    * @param {*=} eventData
+   * @return {boolean}
    */
   dispatchEventToListeners(eventType, eventData) {},
 };
 
 /**
  * @unrestricted
  */
 Common.EventTarget.EventDescriptor = class {
   /**
    * @param {!Common.EventTarget} eventTarget
    * @param {symbol} eventType
    * @param {(!Object|undefined)} receiver
    * @param {function(?):?} method
    */
   constructor(eventTarget, eventType, receiver, method) {
     this.eventTarget = eventTarget;
     this.eventType = eventType;
     this.receiver = receiver;
     this.method = method;
   }
 };