Get rid of DeprecatedLayoutImmediately in composite_layout_tests.cc.

This replaces calls to View::DeprecatedLayoutImmediately() with
calls to views::test::RunScheduledLayout(); we want to get
as many clients as possible to stop calling Layout() explicitly.

Bug: 327488620
Change-Id: I20260ffa02db929be40614abc89246c5cc2cff83
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5354356


Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Allen Bauer <kylixrd@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1270492}