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diff --git a/tools/addon-sdk-1.5/packages/api-utils/lib/events.js b/tools/addon-sdk-1.5/packages/api-utils/lib/events.js
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+++ b/tools/addon-sdk-1.5/packages/api-utils/lib/events.js
@@ -0,0 +1,173 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const ERROR_TYPE = 'error',
+      UNCAUGHT_ERROR = 'An error event was dispatched for which there was'
+        + ' no listener.',
+      BAD_LISTENER = 'The event listener must be a function.';
+/**
+ * This object is used to create an `EventEmitter` that, useful for composing
+ * objects that emit events. It implements an interface like `EventTarget` from
+ * DOM Level 2, which is implemented by Node objects in implementations that
+ * support the DOM Event Model.
+ * @see http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-EventTarget
+ * @see http://nodejs.org/api.html#EventEmitter
+ * @see http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/events/EventDispatcher.html
+ */
+const eventEmitter =  {
+  /**
+   * Registers an event `listener` that is called every time events of
+   * specified `type` are emitted.
+   * @param {String} type
+   *    The type of event.
+   * @param {Function} listener
+   *    The listener function that processes the event.
+   * @example
+   *      worker.on('message', function (data) {
+   *          console.log('data received: ' + data)
+   *      })
+   */
+  on: function on(type, listener) {
+    if ('function' !== typeof listener)
+      throw new Error(BAD_LISTENER);
+    let listeners = this._listeners(type);
+    if (0 > listeners.indexOf(listener))
+      listeners.push(listener);
+    // Use of `_public` is required by the legacy traits code that will go away
+    // once bug-637633 is fixed.
+    return this._public || this;
+  },
+
+  /**
+   * Registers an event `listener` that is called once the next time an event
+   * of the specified `type` is emitted.
+   * @param {String} type
+   *    The type of the event.
+   * @param {Function} listener
+   *    The listener function that processes the event.
+   */
+  once: function once(type, listener) {
+    this.on(type, function selfRemovableListener() {
+      this.removeListener(type, selfRemovableListener);
+      listener.apply(this, arguments);
+    });
+  },
+
+  /**
+   * Unregister `listener` for the specified event type.
+   * @param {String} type
+   *    The type of event.
+   * @param {Function} listener
+   *    The listener function that processes the event.
+   */
+  removeListener: function removeListener(type, listener) {
+    if ('function' !== typeof listener)
+      throw new Error(BAD_LISTENER);
+    let listeners = this._listeners(type),
+        index = listeners.indexOf(listener);
+    if (0 <= index)
+      listeners.splice(index, 1);
+    // Use of `_public` is required by the legacy traits code, that will go away
+    // once bug-637633 is fixed.
+    return this._public || this;
+  },
+
+  /**
+   * Hash of listeners on this EventEmitter.
+   */
+  _events: null,
+
+  /**
+   * Returns an array of listeners for the specified event `type`. This array
+   * can be manipulated, e.g. to remove listeners.
+   * @param {String} type
+   *    The type of event.
+   */
+  _listeners: function listeners(type) {
+    let events = this._events || (this._events = {});
+    return events[type] || (events[type] = []);
+  },
+
+  /**
+   * Execute each of the listeners in order with the supplied arguments.
+   * Returns `true` if listener for this event was called, `false` if there are
+   * no listeners for this event `type`.
+   *
+   * All the exceptions that are thrown by listeners during the emit
+   * are caught and can be handled by listeners of 'error' event. Thrown
+   * exceptions are passed as an argument to an 'error' event listener.
+   * If no 'error' listener is registered exception will propagate to a
+   * caller of this method.
+   *
+   * **It's recommended to have a default 'error' listener in all the complete
+   * composition that in worst case may dump errors to the console.**
+   *
+   * @param {String} type
+   *    The type of event.
+   * @params {Object|Number|String|Boolean}
+   *    Arguments that will be passed to listeners.
+   * @returns {Boolean}
+   */
+  _emit: function _emit(type, event) {
+    let args = Array.slice(arguments);
+    // Use of `_public` is required by the legacy traits code that will go away
+    // once bug-637633 is fixed.
+    args.unshift(this._public || this);
+    return this._emitOnObject.apply(this, args);
+  },
+
+  /**
+   * A version of _emit that lets you specify the object on which listeners are
+   * called.  This is a hack that is sometimes necessary when such an object
+   * (exports, for example) cannot be an EventEmitter for some reason, but other
+   * object(s) managing events for the object are EventEmitters.  Once bug
+   * 577782 is fixed, this method shouldn't be necessary.
+   *
+   * @param {object} targetObj
+   *    The object on which listeners will be called.
+   * @param {string} type
+   *    The event name.
+   * @param {value} event
+   *    The first argument to pass to listeners.
+   * @param {value} ...
+   *    More arguments to pass to listeners.
+   * @returns {boolean}
+   */
+  _emitOnObject: function _emitOnObject(targetObj, type, event /* , ... */) {
+    let listeners = this._listeners(type).slice(0);
+    // If there is no 'error' event listener then throw.
+    if (type === ERROR_TYPE && !listeners.length)
+      console.exception(event);
+    if (!listeners.length)
+      return false;
+    let params = Array.slice(arguments, 2);
+    for each (let listener in listeners) {
+      try {
+        listener.apply(targetObj, params);
+      } catch(e) {
+        this._emit('error', e);
+      }
+    }
+    return true;
+  },
+
+  /**
+   * Removes all the event listeners for the specified event `type`.
+   * @param {String} type
+   *    The type of event.
+   */
+  _removeAllListeners: function _removeAllListeners(type) {
+    if (typeof type == "undefined") {
+      this._events = null;
+      return this;
+    }
+
+    this._listeners(type).splice(0);
+    return this;
+  }
+};
+exports.EventEmitter = require("./traits").Trait.compose(eventEmitter);
+exports.EventEmitterTrait = require('./light-traits').Trait(eventEmitter);