https://hg.mozilla.org/releases/mozilla-beta/annotate/2dec3c6c7c90/toolkit/components/url-classifier/HashStore.cpp#l835 Click the "raw" option. Second line, one but last item. I am pretty sure this should give you the verbatim source, but it actually has blame info prepended on every line.
Every other page has "raw" linking to raw-file. I'm not sure why the annotate page is different. I submitted a patch upstream at https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-December/091858.html. Once that is accepted, I'll apply it to hg.mozilla.org. If it isn't submitted, I'll just hack up our custom gitweb_mozilla theme (because I think linking raw-annotate is weird).
This landed upstream. So needinfo me to remind myself to apply this on our end before 4.1 is released.
https://hg.mozilla.org/hgcustom/version-control-tools/rev/4abaf1821d8b7b9803659299139a4f7745a18be1 hgtemplates: replace raw-annotate link with raw-file (bug 1323999)