The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4a27ce9d6c8c89b86063bce752da95bc380a854e

commit 4a27ce9d6c8c89b86063bce752da95bc380a854e
Author: Mark Cogan <marq@google.com>
Date: Thu Jul 19 11:01:42 2018

[iOS] Tune tab grid transitions.

- Fade in the grid toolbars and the other grid cells sooner in the animation (20% delay instead of 40%)
- Start the cell fade-in from 20% opacity (not 0%).
- Adjust the timing of the presentation and dismissal animations.
- Add spring to the resize animations when entering/exiting the grid.
- Adjust the timing curve of the inactive cell appearance animations.
- Match the device corner radius in the "tab" state of the animations (meaning that on iPhone X, the active cell transitions to/from more rounded corners).

Bug:  865028 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Iddea1d4addfe2192f8175f02599eca39c59edffd
Reviewed-on: https://chromium-review.googlesource.com/1142156
Commit-Queue: Mark Cogan <marq@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576437}
[modify] https://crrev.com/4a27ce9d6c8c89b86063bce752da95bc380a854e/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm
[modify] https://crrev.com/4a27ce9d6c8c89b86063bce752da95bc380a854e/ios/chrome/browser/ui/tab_grid/transitions/BUILD.gn
[modify] https://crrev.com/4a27ce9d6c8c89b86063bce752da95bc380a854e/ios/chrome/browser/ui/tab_grid/transitions/grid_to_visible_tab_animator.mm
[modify] https://crrev.com/4a27ce9d6c8c89b86063bce752da95bc380a854e/ios/chrome/browser/ui/tab_grid/transitions/grid_transition_animation.mm
[modify] https://crrev.com/4a27ce9d6c8c89b86063bce752da95bc380a854e/ios/chrome/browser/ui/tab_grid/transitions/tab_to_grid_animator.mm