Mark fast/frames/frame-name-reset.html as flaky on all platforms

TBR=dom-dev@chromium.org

Bug: 993238
Change-Id: Id1b55d9a908ffd38094e33dd4dea261153b72e40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1750473Reviewed-by: Fergus Dall <sidereal@google.com>
Cr-Commit-Position: refs/heads/master@{#686340}

third_party/blink/web_tests/TestExpectations

@@ -6473,4 +6473,5 @@ crbug.com/856601 [ Linux ] external/wpt/generic-sensor/idlharness.https.window.h
 crbug.com/856601 [ Linux ] external/wpt/secure-contexts/idlharness.any.html [ Pass Timeout ]
 
 #Sheriff 2019-08-12
-crbug.com/783154 [ Linux Debug ] virtual/audio-service/media/controls/doubletap-to-jump-backwards.html [ Failure ]
+crbug.com/783154 [ Linux Debug ] virtual/audio-service/media/controls/doubletap-to-jump-backwards.html [ Failure ]
\ No newline at end of file
+crbug.com/993238 fast/frames/frame-name-reset.html [ Pass Failure ]