It's non-standard, hardly used at all, and does nothing that "video.src = video2.currentSrc" doesn't do. We should remove it. This would also mean we can remove the test, which is intermittently failing.
http://code.google.com/p/reply-manager/ is the only thing I can find with Google that would potentially break.
Also pageInfo.js needs to be modified in mozilla-central.
Created attachment 757773 [details] [diff] [review]
Should the test at http://mxr.mozilla.org/comm-central/source/mozilla/content/html/content/test/test_mozLoadFrom.html?force=1 also get removed? That test tests mozLoadFrom looks like (but does not fail atm?).
Created attachment 795271 [details] [diff] [review]
remove leftover test