Worker: Remove legacy non-S13nServiceWorker path from content/renderer/worker/

S13nServiceWorker is now enabled by default. This CL removes unused
non-S13nServiceWorker path and IsServicificationEnabled() checks.

Bug: 926114
Change-Id: Iefd0c5f07cd75d05883dd8be874cf1d804e83fcf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504605
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638042}
4 files changed