Mark js_interop_2_test as failing on dart2js-chrome and dart2js-ff.

tests/html/html.status

Index: tests/html/html.status
diff --git a/tests/html/html.status b/tests/html/html.status
index 6be98c25d869c59be85c5b6f6470fd42f1164e73..155df79891d58ff0ba9a2d8d64ed92f788963c46 100644
--- a/tests/html/html.status
+++ b/tests/html/html.status
@@ -13,6 +13,9 @@ js_interop_3_test: Fail
 js_interop_4_test: Fail
 js_interop_func_passing_test: Fail
 
+[ $compiler == dart2js && ($runtime == chrome || $runtime == ff) ]
+js_interop_2_test: Fail  # Issue 4651
+
 [ $runtime == drt ]
 xhr_cross_origin_test: Skip  # Issue 4502: Passes with --allow-external-pages.
 
@@ -153,10 +156,6 @@ websocket_test: Pass, Fail # FF 10 is uses MozWebSocket, FF 11 uses WebSocket.
 #    (NS_ERROR_DOM_BAD_URI) ...
 xhr_test: Fail
 
-[ $runtime == ff && $system == windows ]
-# TODO(vsm): Investigate why this is only failing on windows.
-js_interop_2_test: Fail
-
 [ $runtime == ie && ($system == linux || $system == macos) ]
 *: Skip