https://chromium-review.googlesource.com/c/chromium/src/+/1256468 will fix this.

Ah sorry, it is not fixed.
The cl https://chromium-review.googlesource.com/c/chromium/src/+/1256468 fixed only for NetworkService flag.

 Issue 893476  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7f452e5a1642ee650fcf70be15b5b9616d3719d6

commit 7f452e5a1642ee650fcf70be15b5b9616d3719d6
Author: Tsuyoshi Horo <horo@chromium.org>
Date: Thu Oct 11 02:24:18 2018

Create subresource_loader_factories for prefetching when ServiceWorkerServicification is enabled

http://crrev.com/c/1256468 was intended to fix the issue that the prefetching
logic of signed exchange doesn't work in service worker controlled pages when
NetworkService is enabled. But the CL doesn't fix the issue with
ServiceWorkerServicification.

This is because |prefetch_loader_factory| is not correctly passed to the
renderer when ServiceWorkerServicification is enbaled.
This CL fix this problem by:
  - Change RenderFrameHostImpl::CommitNavigation() to create
    prefetch_loader_factory using the default factory and pass it to
    the renderer process when ServiceWorkerServicification is enabled.
  - Add ChildURLLoaderFactoryBundle::SetPrefetchLoaderFactory() to set the
    prefetch_loader_factory from RenderFrameImpl::SetupLoaderFactoryBundle().

Bug:  890748 , 892000 
Change-Id: I056f4a550ace20e271f66463350337c961c0eae0
Reviewed-on: https://chromium-review.googlesource.com/c/1272419
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598636}
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/browser/frame_host/render_frame_host_impl.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/browser/loader/prefetch_url_loader_service.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/browser/loader/prefetch_url_loader_service.h
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/browser/web_package/signed_exchange_request_handler_browsertest.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/renderer/loader/child_url_loader_factory_bundle.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/renderer/loader/child_url_loader_factory_bundle.h
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/renderer/render_frame_impl.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/renderer/service_worker/service_worker_context_client.cc
[modify] https://crrev.com/7f452e5a1642ee650fcf70be15b5b9616d3719d6/content/renderer/shared_worker/embedded_shared_worker_stub.cc