[Improved Geo-language] Add improved language locator.

After this change, the improved ulp_language_locator reads (test) data and returns
most spoken language (according to data). Future CL will add production data and
ability to return multiple languages.

- Re-organizing language code locator implementations.
- Adding read-only quad tree implementation.
- Adding new improved ULP language code locator.
- Adding language code locator factory to select implementation.

Bug: 850947
Change-Id: Iae662062e9dd0025d4caa89eceb4df3a1e079a6f
Reviewed-on: https://chromium-review.googlesource.com/c/1358633
Commit-Queue: Alexandre Frechette <frechette@chromium.org>
Reviewed-by: anthonyvd <anthonyvd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620846}
21 files changed