GitLab

If BrowserView::Layout() gets called multiple times while sliding
the top controls is in progress, it could break sliding altogether,
or at least will make its initiation janky.

This CL allows only a single layout to go through once sliding begins.

BUG=1034047, 950981
TEST=Manually, and expanded an existing test.

Change-Id: I7b906fc2956aa455b573083d7cdaa40812141bfb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1968320Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726637}