Keep getting a crash reported on Linux when my tests try to invoke ShouldLoad via JS. Might be nothing, but thought I'd report it anyway. See: https://treeherder.mozilla.org/logviewer.html#?job_id=5640016&repo=try Which is part of my tests: https://treeherder.mozilla.org/#/jobs?repo=try&revision=6f1b4a09b48d

It's not crashing; it's failing a fatal assert. The assert is that the first value passed in (aContentType) is one of our known values. In the try push, the JS is passing Ci.nsIContentPolicy.TYPE_WEB_MANIFEST which: (1) doesn't seem to exist afaict and (2) is not a type that nsMixedContentBlocker knows about.

Ah yeah, I've implemented Ci.nsIContentPolicy.TYPE_WEB_MANIFEST locally (probably why I wasn't able to reproduce :)). Ok, so this is really just a duplicate of bug 1089255.