[123][iOS] Remove CHECK for the SendTabToSelf coordinator

When the SendTabToSelf UI is presented after a Sign-in, there is a
delay between the moment the Sign-in is done and the UI is shown,
allowing the Sync model to get the "other devices" data.
It seems that in some cases, this is slow enough for the user to open
the SendTabToSelf UI another time.

The correct fix is to show a spinner or something indicating to the user
that something is happening. However, considering the usage of this
feature, it is not worth adding this level of complexity.

This CL removes the CHECK, allowing to re-enter the feature.

(cherry picked from commit e1552e9dfb68e3725238d3d55daafd1e30345e34)

Fixed: 326131561
Change-Id: I840705b7290ceb86435cf3b4a56ef643c5a20d7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5340110
Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Mark Cogan <marq@chromium.org>
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1267803}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5349699
Cr-Commit-Position: refs/branch-heads/6312@{#446}
Cr-Branched-From: 6711dcdae48edaf98cbc6964f90fac85b7d9986e-refs/heads/main@{#1262506}

• ios/chrome/browser/ui/browser_view/browser_coordinator.mm[diff]