[iOS] Re-enable testShowJavaScriptAfterNewTabAnimation

This test passes now after crrev.com/c/1769082, but we've noticed some
flake that isn't reproducing.  This CL re-enables it separately so it
can be easily reverted if necessary.

Bug: 989550
Change-Id: If84c590547a57403ad0bd36079550fe98fc53b1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1769354
Auto-Submit: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691016}

ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm

@@ -575,11 +575,6 @@ void TapSuppressDialogsButton() {
 
 // Tests that an alert is presented after a new tab animation is finished.
 - (void)testShowJavaScriptAfterNewTabAnimation {
-  // TODO(crbug.com/989550) Disable broken context menu tests on Xc11b5.
-  if (@available(iOS 13, *)) {
-    EARL_GREY_TEST_DISABLED(@"Test disabled on iOS13.");
-  }
-
   // Load the test page with a link to kOnLoadAlertURL and long tap on the link.
   [self loadPageWithLink];