Sheriffing - disable two flaky layout tests

This CL updates test expectations for two flaky WPT layout tests.

Bug: 1014327, 1014326
Change-Id: I53b47ecf81338df03eaa75e5520db56cb2c6f49f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863027Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706011}

third_party/blink/web_tests/TestExpectations

@@ -2682,7 +2682,7 @@ crbug.com/618969 external/wpt/css/css-grid/subgrid/ [ Skip ]
 crbug.com/1012627 [ Win7 ] external/wpt/css/css-text/line-breaking/line-breaking-021.html [ Failure ]
 
 # ====== New tests from wpt-importer added here ======
-crbug.com/626703 [ Retina ] external/wpt/preload/preload-with-type.html [ Timeout ]
+crbug.com/626703 [ Mac ] external/wpt/preload/preload-with-type.html [ Pass Timeout ]
 crbug.com/626703 [ Win10 ] virtual/omt-worker-fetch/external/wpt/service-workers/service-worker/update-bytecheck.https.html [ Timeout ]
 crbug.com/626703 [ Retina ] virtual/threaded/external/wpt/css/css-animations/animation-opacity-pause-and-set-time.html [ Failure ]
 crbug.com/626703 [ Mac ] external/wpt/html/rendering/non-replaced-elements/form-controls/select-sizing-001.html [ Failure ]
@@ -5747,3 +5747,6 @@ crbug.com/1013779 virtual/scalefactor200/fast/hidpi/static/popup-menu-appearance
 crbug.com/1013779 virtual/scalefactor200/fast/hidpi/static/validation-bubble-appearance-hidpi.html [ Failure Pass ]
 crbug.com/990900 external/wpt/cookie-store/idlharness.tentative.https.any.serviceworker.html [ Pass Timeout ]
 crbug.com/990900 virtual/omt-worker-fetch/external/wpt/fetch/api/idlharness.any.html [ Pass Timeout ]
+
+# Sheriff 2019-10-15
+crbug.com/1014327 [ Mac ] external/wpt/preload/onerror-event.html [ Pass Timeout ]