This is the key change in this patch series; it changes the object we
use for style data (currently nsIStyleRule) identity. It allows
removing some hacks we have to deal with that for StyleRule, and avoids
having to write similar hacks for nsCSSKeyframeRule and nsCSSPageRule
(which are broken without this).
I confirmed locally that it is this patch that fixes both of the todo_is
mochitests, by building and testing with the patch queue through patch
11, and again through patch 12.
--HG--
extra : commitid : AzgBp6KfPhJ