tracking the attributes which appear in CSS selectors, and only firing
a complete reresolution when we change one of those. In the irrelevant-attr
case, we just let the frame update itself and get on with our lives right
away. Fixed 38378, r=brendan, booyah.
Also, when setting an attribute to the same value that it currently holds,
don't think about it especially hard, and _don't_ go anywhere near the
style code. Fixed 21879, r=brendan, boo_yah_.
git-svn-id: svn://10.0.0.236/trunk@69948 18797224-902f-48f8-a5cc-f745e15eee43
f792546214