OMT worker fetch: Use WorkerResourceTimingNotifier for worker module scripts

This is a follow-up CL of https://crrev.com/c/1525242. This theoretically
plumbs resource timing info for worker module scripts to appropriate
performance timelines, but there are some limitations as we don't fully
implement module scripts in workers. Specifically,
- Resource timing info is plumbed for module dedicated workers but there
  is no test yet.
- Module shared workers haven't been implemented yet.
- Module service workers are partially implemented but don't support
  resource timing yet (See bug 954005).
- Worklets don't support resource timing yet.

This CL also changes to pass WorkerResourceTimingNotifier as a
reference (not a pointer) to make sure that callsites pass a
valid WorkerResourceTimingNotifier, except for crossing threads
cases (i.e., in WorkerThread and ThreadedWorkletObjectProxy).

Bug: 928146, 954005
Change-Id: Ie65b396b686fd7824e66496cd999b39f643009c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1583166
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654236}
30 files changed