I've been seeing a pattern of "unsafe" CPOWs causing our browser-chrome mochitests to go intermittently orange. Generally, it seems that a test randomly turns orange, gets starred and ignored until RyanVM or another one of our sheriffs gets tired of seeing it and needinfos somebody in the hopes of fixing it.
Rather than continue on this path, it would be good to just fix these unsafe CPOWs. They are already banned (via pref) in browser code proper for this very reason and we'd like to get rid of CPOWs entirely one day. To further that objective, I generated a list  of CPOW uses in a Linux mochitest run. The list has the filename of the test followed by a list of line numbers in the test file where we detected CPOW usage. If the CPOW was in a different file (i.e. head.js), that is listed below the test.
In general, most of these tests should be easy to fix either with ContentTask or using an API on <browser> that has already done the correct forwarding. If you would like examples, I've fixed several tests in  and . I'm also always happy to answer questions or help out.
So, if you have a few spare cycles, please grab a test and fix it!