GitLab

Fix thread misusage in TabGridDialogParentTest

There are several tests in TabGridDialogParentTest that don't run on
UI thread by default. This CL modifies such tests so that things should
run on UI thread are moved to UI thread.

Bug: None
Change-Id: Ia3064132e36de673f35ae1619d281f597002c6ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2148282
Commit-Queue: Yue Zhang <yuezhanggg@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759300}