[ios] Fix tab grid top toolbar height

The custom intrinsic height was removed in crrev.com/c/1397639.
UIToolbar does not automatically adjust its height to its inner content.

This CL reintroduces the intrinsic height.

This fixes a bug where the height was short when cold starting in
landscape.

TBR=mrsuyi@chromium.org

Bug: 933330
Change-Id: I4fa044c84af692f0eafceeaee388f8f601fb23a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1600365
Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Auto-Submit: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657914}
1 file changed