Update test expectations for flaky test

Bug: 1033387
Change-Id: Iae271c16384dfa3282e13765693e71e6be810cdf
TBR: jbroman@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1988508Reviewed-by: Ian Clelland <iclelland@chromium.org>
Commit-Queue: Ian Clelland <iclelland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728556}

third_party/blink/web_tests/TestExpectations

@@ -7109,7 +7109,7 @@ crbug.com/1006759 inspector-protocol/heap-profiler/heap-snapshot-with-no-detache
 # Sheriff 2019-12-13
 crbug.com/1032451 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/idlharness.https.window.html [ Failure Timeout Pass ]
 crbug.com/1033852 [ Win7 ] virtual/omt-worker-fetch/external/wpt/fetch/api/idlharness.any.sharedworker.html [ Failure ]
-crbug.com/1033387 [ Mac ] http/tests/portals/crbug-1031677.html [ Pass Timeout ]
+crbug.com/1033387 [ Mac ] http/tests/portals/crbug-1031677.html [ Pass Timeout Crash ]
 
 # Sheriff 2019-12-16
 crbug.com/1034374 http/tests/devtools/tracing/timeline-worker-events.js [ Pass Failure ]