fix the type of Event.hasListener and Event.hasListeners()
This is documented at
and the existing types that are wrong appear to just be copy'n'paste errors.
@@ -4582,17 +4582,15 @@ ChromeInputImeOnKeyEventEvent.prototype.removeListener = function(callback) {};
/**
* @param {function(string, !ChromeKeyboardEvent): (boolean|undefined)} callback
* callback.
- * @return {undefined}
+ * @return {boolean}
*/
ChromeInputImeOnKeyEventEvent.prototype.hasListener = function(callback) {};
/**
- * @param {function(string, !ChromeKeyboardEvent): (boolean|undefined)} callback
- * callback.
- * @return {undefined}
+ * @return {boolean}
*/
-ChromeInputImeOnKeyEventEvent.prototype.hasListeners = function(callback) {};
+ChromeInputImeOnKeyEventEvent.prototype.hasListeners = function() {};
/**
@@ -6739,16 +6737,15 @@ WebRequestBaseEvent.prototype.removeListener = function(listener) {};
/**
* @param {LISTENER} listener Listener function.
- * @return {undefined}
+ * @return {boolean}
*/
WebRequestBaseEvent.prototype.hasListener = function(listener) {};
/**
- * @param {LISTENER} listener Listener function.
- * @return {undefined}
+ * @return {boolean}
*/
-WebRequestBaseEvent.prototype.hasListeners = function(listener) {};
+WebRequestBaseEvent.prototype.hasListeners = function() {};
/**
@@ -6814,16 +6811,15 @@ WebRequestOnErrorOccurredEvent.prototype.removeListener = function(listener) {};
/**
* @param {function(!Object): void} listener Listener function.
- * @return {undefined}
+ * @return {boolean}
*/
WebRequestOnErrorOccurredEvent.prototype.hasListener = function(listener) {};
/**
- * @param {function(!Object): void} listener Listener function.
- * @return {undefined}
+ * @return {boolean}
*/
-WebRequestOnErrorOccurredEvent.prototype.hasListeners = function(listener) {};
+WebRequestOnErrorOccurredEvent.prototype.hasListeners = function() {};
/**
