Mark more flaky idlharness tests on WebKit Linux MSAN

Timeouts on

https://ci.chromium.org/p/chromium/builders/ci/WebKit%20Linux%20MSAN/3561
https://ci.chromium.org/p/chromium/builders/ci/WebKit%20Linux%20MSAN/3564

Change-Id: Ibcc0a9aefb2203e673670b2f55d0c32430b5a834
NoTry: True
Tbr: xiaochengh@chromium.org
Bug: 856601
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1982878Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727600}

third_party/blink/web_tests/MSANExpectations

@@ -362,3 +362,7 @@ crbug.com/856601 [ Linux ] virtual/omt-worker-fetch/external/wpt/fetch/cors-rfc1
 # Note to sheriffs: Timeouts about "idlharness" or "interfaces" are usually crbug.com/856601.
 crbug.com/856601 [ Linux ] external/wpt/secure-contexts/idlharness.any.html [ Pass Timeout ]
 crbug.com/856601 [ Linux ] external/wpt/compression/compression-stream.tentative.any.serviceworker.html [ Pass Timeout ]
+
+# Sheriff 2019-12-27
+crbug.com/856601 [ Linux ] external/wpt/battery-status/idlharness.https.window.html [ Pass Timeout ]
+crbug.com/856601 [ Linux ] external/wpt/permissions/idlharness.any.html [ Pass Timeout ]