Navigation: Move |service_worker_handle_| from NavigationHandleImpl.

This includes removing the related functions, and in-lining them in
NavigationRequest instead.

Bug: 916537
Change-Id: I6c7ca57d533a43067607dc761469738702374669
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1720835
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Lowell Manners <lowell@chromium.org>
Commit-Queue: Mohamed Abdelhalim <zetamoo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#681757}