The style system already atomizes all CustomIdent values, which means that we're
just wasting memory and CPU by doing string copies all over the place.
This patch fixes it. This also simplifies further changes to use as much of the
rust data structures as possible.
I had to switch from nsTHashtable to mozilla::HashTable because the former
doesn't handle well non-default-constructible structs (like NamedLine, which
now has a StyleAtom, which is not default-constructible).
Differential Revision: https://phabricator.services.mozilla.com/D35119
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extra : moz-landing-system : lando
Right now we do a lot of useless string copying. In order to avoid transcoding
to utf-16 during layout, make sure to use nsCString at a few related places.
I may revisit this since we're storing other line names as atoms in some places.
So it may be better to just use atoms everywhere.
But that'd be a different patch either way.
Depends on D35116
Differential Revision: https://phabricator.services.mozilla.com/D35117
--HG--
extra : moz-landing-system : lando