The problem is when it's falling back to the network due to no fetch handler or no respondWith, the request goes to the ResourceDispatcherHostImpl and it's handled by the appcache.
We may need to fallback directly to the network instead of going through the RDHI, or we may need to add something to notify it's after service worker handled the request. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/684a5ad2a671a91a7feb214703f8decc3fc83d10

commit 684a5ad2a671a91a7feb214703f8decc3fc83d10
Author: Makoto Shimazu <shimazu@chromium.org>
Date: Tue May 29 08:20:50 2018

NetS13nSW: Skip interception if a subresource loader is attached

When ServiceWorkerServicification is on and NetworkService is off, the request
will be intercepted by both of request interceptors living in
NavigationURLLoaderImpl and URLRequestInterceptors created in
ResourceDispatcherHostImpl. However, in the current implementation, the network
request intercepted by a request intercepter could be intercepted in the
ResourceDispatcherHostImpl again when a service worker intercepted the request
skips handling the request. This CL is to avoid the double interception.

Bug:  846232 
Change-Id: Iec6e770a9ba620a9592cd41872d1d8572b9e8bf4
Reviewed-on: https://chromium-review.googlesource.com/1074782
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562368}
[modify] https://crrev.com/684a5ad2a671a91a7feb214703f8decc3fc83d10/content/browser/loader/navigation_url_loader_impl.cc
[modify] https://crrev.com/684a5ad2a671a91a7feb214703f8decc3fc83d10/content/browser/service_worker/service_worker_request_handler.cc
[delete] https://crrev.com/916133ff547890afc86faa3f5d81c2ae0f978038/third_party/WebKit/LayoutTests/virtual/service-worker-servicification/external/wpt/service-workers/service-worker/appcache-ordering-main.https-expected.txt