[ios] Add back missing top safe area insets

Bug: 826369
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I76ad9c0e15b1ff7599ce71d68053a2757e67fa6f
Reviewed-on: https://chromium-review.googlesource.com/1016705
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#552076}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 5d52cbf95169733b2c623e10e90dbd28c5faf7f8
9 files changed