I think if we could see the information about Service Worker Navigation Preload in chrome://serviceworker-internals, it was easy to debug the issue 795813.
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/8abc2815165c7bdeade44a4aacd0252abe7494aa commit 8abc2815165c7bdeade44a4aacd0252abe7494aa Author: Tsuyoshi Horo <horo@chromium.org> Date: Tue Jan 16 03:58:26 2018 Show NavigationPreload information in chrome://serviceworker-internals Bug: 801424 Change-Id: Ic48d41067b14f2fb39b85a24843c7d6646692004 Reviewed-on: https://chromium-review.googlesource.com/863542 Commit-Queue: Tsuyoshi Horo <horo@chromium.org> Reviewed-by: Matt Falkenhagen <falken@chromium.org> Cr-Commit-Position: refs/heads/master@{#529362} [modify] https://crrev.com/8abc2815165c7bdeade44a4aacd0252abe7494aa/content/browser/resources/service_worker/serviceworker_internals.html [modify] https://crrev.com/8abc2815165c7bdeade44a4aacd0252abe7494aa/content/browser/service_worker/service_worker_info.cc [modify] https://crrev.com/8abc2815165c7bdeade44a4aacd0252abe7494aa/content/browser/service_worker/service_worker_info.h [modify] https://crrev.com/8abc2815165c7bdeade44a4aacd0252abe7494aa/content/browser/service_worker/service_worker_internals_ui.cc [modify] https://crrev.com/8abc2815165c7bdeade44a4aacd0252abe7494aa/content/browser/service_worker/service_worker_registration.cc
Comment 1 by horo@chromium.org
, Jan 16 2018