[Sheriff] Disable flaky test BrowserTest.WindowOpenClose2 on Windows.

It started flaking on https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Win7%20Tests%20%28dbg%29%281%29/70474

TBR=fsamuel

Bug: 823043
Change-Id: I23a000160c81ed75a277331a6739095958ff6e77
Reviewed-on: https://chromium-review.googlesource.com/1149097
Reviewed-by: Derek Cheng <imcheng@chromium.org>
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577730}
1 file changed