Worker: Add [Replaceable] to SharedWorkerGlobalScope.name

The HTML spec requires SharedWorkerGlobalScope.name has [Replaceable]:
https://html.spec.whatwg.org/multipage/workers.html#shared-workers-and-the-sharedworkerglobalscope-interface

This CL also fixes a test expectation of
wpt/workers/interfaces/SharedWorkerGlobalScope/name/setting.html. The name
attribute is now replaceable, so the result should be replaced. Firefox fails
the test because of this wrong expectation:
https://wpt.fyi/results/workers/interfaces/SharedWorkerGlobalScope/name/setting.html?label=stable&aligned&q=%2Fname%2Fsetting.html

Bug: 875714
Change-Id: Id04ae30895a2de4a07e30f49dc1189bb9742f6b9
Reviewed-on: https://chromium-review.googlesource.com/c/1347962
Reviewed-by: Kent Tamura <tkent@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610383}
6 files changed