GitLab

This CL:

- Allows extensions to specify no static Rulesets as part of the
"rule_resources" manifest key or optionally to omit the
"declarative_net_request" manifest key. Since we support dynamic rules,
we should allow this. Also, we plan to implement the ability to toggle
the set of enabled static rulesets, under which a state with no enabled
static rulesets should be allowed.

- Since we now allow extensions to not specify any static rulesets,
don't fail if an extension calls updateDynamicRules or getDynamicRules
if the extension doesn't have any registered rulesets.

- Also, move the book-keeping for the set of extensions with active
rulesets to RulesetManager from RulesMonitorService. RulesetManager
already maintains the set of active rulesets, so it should be the source
of truth for this info.

BUG=754526, 953894, 931967

Change-Id: I3d9c6eae5f4d0691b8272ffa4e81c6791f273c65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2125691Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756095}