Split css unit test rule from blink/renderer/core:unit_tests.

Bug: 927857
Change-Id: Ic60dc759fb88bbd12d3114994756f34cd4c6afea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1532963
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Aran Gilman <gilmanmh@google.com>
Auto-Submit: Aran Gilman <gilmanmh@google.com>
Cr-Commit-Position: refs/heads/master@{#655309}
2 files changed