GitLab

Introduce RulesetSource struct to be used for indexing code. This should help
make the indexing code a bit more generic since it does not need to assume the
location of the json and indexed ruleset files.

BUG=930961

Change-Id: I9f6f63434adbe8d3fbc0e5148c466c578c3dd422
Reviewed-on: https://chromium-review.googlesource.com/c/1466281Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632371}