[OnionSoup] Remove ServiceWorkerUtils::IsServicificationEnabled()

This CL removes ServiceWorkerUtils::IsServicificationEnabled() and uses
blink::ServiceWorkerUtils::IsServicificationEnabled() instead.

BUG=789854

Change-Id: I89031cec6ccaa23a8ea0d711fb0e7684d9a370b1
Reviewed-on: https://chromium-review.googlesource.com/1125535
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Han Leon <leon.han@intel.com>
Cr-Commit-Position: refs/heads/master@{#574064}
29 files changed