Make addEventListener/removeEventListener arguments non-optional

third_party/WebKit/LayoutTests/fast/js/function-length.html

Index: third_party/WebKit/LayoutTests/fast/js/function-length.html
diff --git a/third_party/WebKit/LayoutTests/fast/js/function-length.html b/third_party/WebKit/LayoutTests/fast/js/function-length.html
index e95219b1bda4e738f06ee5cc55770bfb00de356d..147d5aba48ad5f09c5d9950c1a561912b58f165e 100644
--- a/third_party/WebKit/LayoutTests/fast/js/function-length.html
+++ b/third_party/WebKit/LayoutTests/fast/js/function-length.html
@@ -11,9 +11,8 @@ shouldBe('window.confirm.length', '0');
 shouldBe('window.open.length', '2');
 shouldBe('window.setTimeout.length', '1');
 shouldBe('window.clearTimeout.length', '0');
-// addEventListener.length should be 2, but legacy content calls with 0 or 1
-// argument. See http://crbug.com/249598
-shouldBe('window.addEventListener.length', '0');
+shouldBe('window.addEventListener.length', '2');
+shouldBe('window.removeEventListener.length', '2');
 shouldBe('window.postMessage.length', '2');
 shouldBe('window.dispatchEvent.length', '1');
 shouldBe('window.openDatabase.length', '4');