Properly destroy TabGridDialog and TabGridSheet

This is a follow-up CL for
https://chromium-review.googlesource.com/c/chromium/src/+/1653835.
Properly destroy components in TabGroupUiCoordinator and
GridTabSwticherCoordinator.

Bug: 972217
Change-Id: Iadf02b18f74b5ef78c0a2aae56f208d5db4ba9b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660697
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: Yue Zhang <yuezhanggg@google.com>
Cr-Commit-Position: refs/heads/master@{#669531}
2 files changed