Fix crash in |InputMethodController::ExtendSelectionAndDelete|

The crash is introduced by this CL[1]. In |ExtendSelectionAndDelete|
layout can be dirty again after |SetSelectionOffsets| call. We should
make sure that layout is clean before getting visible selection.

[1]: https://chromium-review.googlesource.com/c/chromium/src/+/5472192

Bug: 336992377
Change-Id: Ib165278ca332f3511de635bd328c600675fa18ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5963237
Commit-Queue: Koji Ishii <kojii@chromium.org>
Auto-Submit: Siye Liu <siliu@microsoft.com>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1375679}