This now means that using a class/id/attribute selector in one scope will
not cause style recalcs in other scopes in the page when something with
that feature changes.
It also removes an iteration over all the scopes that used to collect
features.
I also removed all the extra cases around adding/removing classes since
the general case can handle them.
In addition I removed the check for classStringHasClassName which looked
to see if the string was all whitespace. This check dated way back to
fixing an assert in code we don't even have anymore. Assertion fix aside
all the extra check optimized for was if you wrote class=" " with no
names, which will now cause an extra malloc of the SpaceSplitString::Data.
This seems super rare, it makes more sense to not scan the class string
every time the list of classes changes which is far more common than
setting a string of only whitespace.
R=ojan@chromium.org
Review URL: https://codereview.chromium.org/837883002
This caused us to lose our gn check certification. :(
Turns out gn check was just ignoring all the header
paths it didn't understand and so gn check passing
for sky wasn't meaning much. I tried to straighten
out some of the mess in this CL, but its going to take
several more rounds of massaging before gn check
passes again. On the bright side (almost) all of
our headers are absolute now. Turns out my script
(attached to the bug) didn't notice ../ includes
but I'll fix that in the next patch.
R=abarth@chromium.org
BUG=435361
Review URL: https://codereview.chromium.org/746023002
