Add flake expectations for tests blocking wpt import

Bug: 1168130
Change-Id: I6f7e3a0e5b6b9d5eb758c368d61d5366cbd3d6d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2637455
Auto-Submit: Luke Z <lpz@chromium.org>
Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Luke Z <lpz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844780}

third_party/blink/web_tests/TestExpectations

@@ -5856,6 +5856,10 @@ crbug.com/1163176 external/wpt/css/css-sizing/aspect-ratio/replaced-element-031.
 crbug.com/1163176 external/wpt/css/css-sizing/aspect-ratio/replaced-element-032.html [ Failure ]
 crbug.com/1163178 external/wpt/svg/embedded/image-embedding-svg-with-auto-height.svg [ Failure ]
 
+# Wpt importer sheriff 2021-01-19
+crbug.com/1168130 external/wpt/css/css-flexbox/abspos/position-absolute-012.html [ Pass Failure ]
+crbug.com/1168130 external/wpt/css/css-flexbox/abspos/position-absolute-013.html [ Pass Failure ]
+
 # Sheriff 2020-12-14
 crbug.com/1046784 http/tests/devtools/console/console-context-selector.js [ Pass Timeout ]