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- Removed background color on left-icon and added tint
- Changed font-style
- New dismiss icon at top-right
- Changed button corner radius

Screenshot of what the AFTER looks like for iPhone X and iPhone 8:
https://screenshot.googleplex.com/vZw7f4UomSt

Bug: 843571
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I9a0446897298a3d5e51def78de61022e81115c77
Reviewed-on: https://chromium-review.googlesource.com/1068136Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Peter Lee <pkl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560996}