Remove raw pointer to RuleData* from MatchedRule.

We're not allowed to have pointers (of any kind) from DISALLOW_NEW()
objects into other DISALLOW_NEW() objects.

After some investigation, it turns out we only need a few elements
from RuleData, not the entire pointer -- and we can squeeze those
into MatchedRule without increasing its size. We take a small
(0—2%) hit to the style perftest, due to pointer compression and
the increased cost of constructing a MatchedRule.

Bug: 389707046
Change-Id: I9ea1d0c23e2579387e8863d23d9a3bd8fe15a9dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6181900
Auto-Submit: Steinar H Gunderson <sesse@chromium.org>
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1408886}