Advance lifecycle to kInStyleRecalc before resolving style in tests.

Trying to add DCHECKs to avoid StyleResolver::StyleForElement() and
PseudoStyleForElement() caused a few unit tests to break. This CL
advances the lifecycle to allow StyleForElement() to be called on a
style-dirty tree in style_resolver_test.cc.

Change-Id: Ice81c60cd704f6b718b2a781adf93bc069294446
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2352732
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797592}