status-bubble: delays destruction for 10 seconds

Perf data indicates deleting the bubble can be expensive. This is because
the deletion of a top-level widget triggers synchronous operations with viz.
During startup there may be lots of things happening in viz, so, delay deletion
for 10 seconds in hopes of things having settled down.

BUG=943268
TEST=covered by tests

Change-Id: Id1d56997553b01f9cf64a3866c013f20d0b75c86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1532583
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642715}
3 files changed