[iOS] Disable failing test

WebStateDelegateTabHelperTest.GetJavaScriptDialogPresenter is failing.
Disabling it.

TBR=eugenebut@chromium.org

Bug: 1038514
Change-Id: I175e3fc76f1f71e60bc6bd79027f7722ea7c3b0c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1984999
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727865}

ios/chrome/browser/web/web_state_delegate_tab_helper_unittest.mm

@@ -66,7 +66,8 @@ TEST_F(WebStateDelegateTabHelperTest, OnAuthRequired) {
 
 // Tests that GetJavaScriptDialogPresenter() returns an overlay-based JavaScript
 // dialog presenter.
-TEST_F(WebStateDelegateTabHelperTest, GetJavaScriptDialogPresenter) {
+// TODO(crbug.com/1038514): Re-enable this test.
+TEST_F(WebStateDelegateTabHelperTest, DISABLED_GetJavaScriptDialogPresenter) {
   // Verify that the delegate returns a non-null presenter.
   web::JavaScriptDialogPresenter* presenter =
       delegate()->GetJavaScriptDialogPresenter(web_state());