http/tests/security/frameNavigation/xss-ALLOWED-top-navigation-after-postMessage.html has been failing on Site Isolation bots since https://build.chromium.org/p/chromium.fyi/builders/Site%20Isolation%20Linux/builds/13311.

Nate, looks like this was caused by your https://codereview.chromium.org/2617773002.  Looks like we had a previous expectation for this in FlagExpectations/site-per-process, expecting the test to fail with a timeout, but now it fails with a text diff (the output has PASS but is missing the console log warning).  Is there perhaps some sort of race in --site-per-process where the console warning doesn't get logged in time?  

To repro:
  $ third_party/WebKit/Tools/Scripts/run-webkit-tests \
      --additional-drt-flag=--site-per-process \
      -t gn -v http/tests/security/frameNavigation/xss-ALLOWED-top-navigation-after-postMessage.html


We could probably just adjust the test's expectations for now in FlagExpectations/site-per-process, since you've got a CL in progress to switch the test back to expect that navigation to fail.