GitLab

- Updates SigninPromoView to support a new UI Layout based on UIRefresh Phase 1 flag and a new
flag received on init.
- Some minor refactoring to stop calling self on init in SigninPromoView.

Screenshots:
https://drive.google.com/open?id=1FnR436FEX9_3GwFbIIrJsQ8qHZOdqJpl
https://drive.google.com/open?id=1__aPHb1ye3WkiHKHJp9kIyJ6hhABq1Y6
https://drive.google.com/open?id=1ibjz3nnXHBrO_akJm4e9tgghpD85f3u0
https://drive.google.com/open?id=1dCVkiMW1IMQjWkxcegVxi8r1PLh5ZCqM

Bug: 805188
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I1268388da06c57eb9c1610c3547314929bb8c107
Reviewed-on: https://chromium-review.googlesource.com/1107216
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570864}