[OnionSoup] Clean up content/common/service_worker/service_worker_types.h

This CL removes those unnecessary things from
content/common/service_worker/service_worker_types.h, follow-up CLs will
remove all dependencies on it from all code other than
content/browser/service_worker/, then move/merge it into
content/browser/service_worker/ finally.

BUG=789854

Change-Id: Ied002b16718d345bd038f11c4486d703cdc4bdfb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692206
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Leon Han <leon.han@intel.com>
Cr-Commit-Position: refs/heads/master@{#676327}