GitLab

Add the function skeleton for getMatchedRules along with types required
for it in the .idl.

Once again, skipping presubmit as the idl parser fails weirdly as seen
in crbug.com/956368

NOPRESUBMIT=true

Bug: 967942
Change-Id: I76c79e3de1c008d43474dec4cbec3a7b476f5374
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1639518
Commit-Queue: Kelvin Jiang <kelvinjiang@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665667}