The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/65cb8ce1797fa6131ac787377d8acfb94aa3d370

commit 65cb8ce1797fa6131ac787377d8acfb94aa3d370
Author: falken <falken@chromium.org>
Date: Mon Jun 27 03:19:40 2016

service worker: Add net_log for fetch event dispatch

Many interesting things happen in ServiceWorkerFetchDispatcher. Add logging for easier
debugging when something goes wrong.

BUG= 622963 

Review-Url: https://codereview.chromium.org/2086093004
Cr-Commit-Position: refs/heads/master@{#402105}

[modify] https://crrev.com/65cb8ce1797fa6131ac787377d8acfb94aa3d370/content/browser/service_worker/service_worker_browsertest.cc
[modify] https://crrev.com/65cb8ce1797fa6131ac787377d8acfb94aa3d370/content/browser/service_worker/service_worker_fetch_dispatcher.cc
[modify] https://crrev.com/65cb8ce1797fa6131ac787377d8acfb94aa3d370/content/browser/service_worker/service_worker_fetch_dispatcher.h
[modify] https://crrev.com/65cb8ce1797fa6131ac787377d8acfb94aa3d370/content/browser/service_worker/service_worker_url_request_job.cc
[modify] https://crrev.com/65cb8ce1797fa6131ac787377d8acfb94aa3d370/net/log/net_log_event_type_list.h

Here's what I want to do for this still:
- netlog for ServiceWorkerWriteToCacheJob
- netlog for ServiceWorkerReadFromCacheJob
- netlog for ServiceWorkerURLRequestJob
- Have detailed netlog including HTTP headers.
- https://codereview.chromium.org/2086093004 is an example of a good way to add netlog, I think. The first attempt added too many event types instead of doing Begin/End events with lots of params (see SERVICE_WORKER_ERROR_STREAM_ABORTED etc used by ServiceWorkerURLRequestJob, those could be params instead of events).

This will be superseded by servicification.