[ios] Move SDK target to 12.0.

Moves minimum deployment target from iOS11 to iOS12.

Bug: 976348
Change-Id: Ie49c322e42837350fed9b08b54086ea0e790ea93
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1706506
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Misha Efimov <mef@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#680013}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: d5c88f6ec2414efc260794e05dbaf9e925999f1d
1 file changed