GitLab

Currently the single static indexed ruleset for an extension is stored
at $extension_path/_metadata/generated_indexed_ruleset. Since we plan to
support multiple static rulesets, we need to store multiple indexed
rulesets.

This CL changes the static indexed ruleset location to
$extension_path/_metadata/generated_indexed_rulesets/_ruleset$ruleset_id.
This helps us move the code away from the assumption of a single static
ruleset.

As a result of this existing extensions with a DNR ruleset will
initially fail to load the DNR ruleset. However the re-indexing logic
should step in and ensure the extension works seamlessly. A side-effect
for these extensions is that the old indexed ruleset will remain on
disk. However this is ok since the API is still on beta and doesn't have
significant usage yet. Furthermore, we do periodically clean up
extension folders after extension updates.

BUG=754526

Change-Id: Id3bd6c1e25fde4ceb1a34f9f84c67bfa340790ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094626
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751607}