Move kApplicationLocale pref to components/language/

We need to use the pref in components, move the pref to components/language/
so it can be accessed.

Bug: 729596
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I37cb0b6fd9976ff8fc6d3239e01d4f38fc7b73f4
Reviewed-on: https://chromium-review.googlesource.com/1135198
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Ran Ji <ranj@chromium.org>
Commit-Queue: Ran Ji <ranj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575190}
34 files changed