VT: Fix a flaky test by adding the hidden div.
This test styles the hidden div to keep the animation running, but
doesn't actually add the hidden div. The patch addresses that
Bug: 355127919
Change-Id: Ib3e2bb5e25471f18886ab985904953cfdc042f6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5747070
Commit-Queue: Vladimir Levin vmpstr@chromium.org
Reviewed-by: Khushal Sagar khushalsagar@chromium.org
Cr-Commit-Position: refs/heads/main@{#1334372}