Mark a couple of virtual/plz-dedicated-worker service-worker as faliky timing out

The following tests are timing out on Win7 Tests bot
- virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/registration-updateviacache.https.html
- virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/update-bytecheck-cors-import.https.html

TBR=nhiroki

Bug: 1150700
Change-Id: I582243fe4e91cb9ee46c90b430efe03f6f7c7c83
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2547650Reviewed-by: Keishi Hattori <keishi@chromium.org>
Commit-Queue: Keishi Hattori <keishi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829099}

third_party/blink/web_tests/TestExpectations

@@ -5991,6 +5991,10 @@ crbug.com/1146560 [ Win ] fast/canvas/color-space/canvas-createImageBitmap-e_srg
 # Sheriff 2020-11-12
 crbug.com/1148259 [ Mac ] external/wpt/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html [ Failure ]
 
+# Sheriff 2020-11-19
+crbug.com/1150700 [ Win ] virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/registration-updateviacache.https.html [ Pass Timeout ]
+crbug.com/1150700 [ Win ] virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/update-bytecheck-cors-import.https.html [ Pass Timeout ]
+
 # Disable flaky tests when scroll unification is enabled
 crbug.com/1130020 virtual/scroll-unification/fast/scrolling/scrollbars/scrollbar-mousedown-move-mouseup.html [ Pass Failure Timeout ]
 crbug.com/1130020 virtual/threaded-prefer-compositing/fast/scrolling/scrollbars/scrollbar-mousedown-move-mouseup.html [ Pass Failure Timeout ]