Update the rest of SwitchAccess to ES2015

Bug: 884297
Change-Id: Iff20201277983eed3d851279ed6e7042ae17d250
Reviewed-on: https://chromium-review.googlesource.com/1237554
Commit-Queue: Zach Helfinstein <zhelfins@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593271}
9 files changed