Mark offscreencanvas.resize.html flaky

offscreencanvas.resize.html is flaky on Mac, Linux and Windows. It was
only marked flaky for Mac and Linux. Add Windows to the list.

Bug: 1093291
Change-Id: I95c06f2a4c8424a8f7c038473f7975cb4e21b0fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2249341Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Reviewed-by: Yi Xu <yiyix@chromium.org>
Commit-Queue: Yi Xu <yiyix@chromium.org>
Cr-Commit-Position: refs/heads/master@{#779510}

third_party/blink/web_tests/TestExpectations

@@ -6745,8 +6745,7 @@ crbug.com/1093003 [ Mac ] external/wpt/html/rendering/replaced-elements/embedded
 
 # Sheriff 2020-06-10
 crbug.com/1093429 [ Mac ] external/wpt/webrtc/RTCPeerConnection-getStats.https.html [ Failure ]
-crbug.com/1093709 [ Mac ] external/wpt/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.resize.html [ Pass Failure ]
-crbug.com/1093709 [ Linux ] external/wpt/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.resize.html [ Pass Failure ]
+crbug.com/1093709 external/wpt/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.resize.html [ Pass Failure ]
 
 # Sheriff 2020-06-11
 crbug.com/1093026 [ Linux ] http/tests/security/offscreencanvas-placeholder-read-blocked-no-crossorigin.html [ Pass Failure ]