Flip S13nServiceWorker virtual test to disable the flag

Currently NetS13nServiceWorker is enabled by default, and we don't have tests
excercising non-S13nServiceWorker path. This flips the test to enable
S13nServiceWorker to disabling S13nServiceWorker forcefully.

Bug: 715640
Change-Id: I8ba3401989dcd9da46e24cd7dc0500f66a200741
Reviewed-on: https://chromium-review.googlesource.com/c/1365050
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614295}
10 files changed