Mark iframe-popup-same-origin-allow-popups.https.html as Timeout not failure

The test is flaky with timeouts not failures.

Bug: 1042199
Change-Id: Ia2079d2437e7bc158841c8c7aee855aaa088dae1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2002621
Commit-Queue: Pâris Meuleman <pmeuleman@chromium.org>
Commit-Queue: Arthur Hemery <ahemery@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Auto-Submit: Pâris Meuleman <pmeuleman@chromium.org>
Reviewed-by: Arthur Hemery <ahemery@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732410}

third_party/blink/web_tests/TestExpectations

@@ -6378,7 +6378,7 @@ crbug.com/1041973 external/wpt/html/semantics/forms/constraints/form-validation-
 crbug.com/1041973 virtual/web-components-v0-disabled/external/wpt/html/semantics/forms/constraints/form-validation-reportValidity.html [ Pass Failure ]
 
 # Sheriff 2020-01-15
-crbug.com/1042199 external/wpt/html/cross-origin-opener-policy/iframe-popup-same-origin-allow-popups.https.html [ Pass Failure ]
+crbug.com/1042199 external/wpt/html/cross-origin-opener-policy/iframe-popup-same-origin-allow-popups.https.html [ Pass Timeout ]
 crbug.com/1041451 virtual/gpu-rasterization-disable-yuv/images/yuv-decode-eligible/color-profile-filter.html [ Pass Failure ]
 
 # Disabled for landing devtools changes