//components/signin: Move switches/prefs into shared target

We'll see where things go long-term, but for now, these seem more
intuitively like shared code than internal code.

Bug: 901859
Change-Id: Ie3caff7ab36afa2453baa80199fd612e4ab9dfbb
Reviewed-on: https://chromium-review.googlesource.com/c/1331472
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607969}
1 file changed