[Sheriff] Update web_tests expectations

TBR=tkent@chromium.org

Bug: 1113791
Change-Id: I4adf0f4a0411cbba1ce414337b3c71340fd5039a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339231Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Commit-Queue: Fabio Tirelo <ftirelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795557}

third_party/blink/web_tests/TestExpectations

@@ -6841,3 +6841,6 @@ crbug.com/1112771 external/wpt/css/css-grid/grid-definition/grid-inline-template
 # Sheriff 2020-08-05
 crbug.com/1113050 fast/borders/border-radius-mask-video-ratio.html [ Pass Failure ]
 crbug.com/1113127 fast/canvas/downsample-quality.html [ Pass Failure Crash ]
+
+# Sheriff 2020-08-06
+crbug.com/1113791 [ Win ] media/video-zoom.html [ Pass Failure ]