GitLab

Non-immersive fullscreen mode (i.e. youtube video pressed with
app fullscreen button) is too easy to exit by accident by tapping on
the top/bottom edge. This CL changes that logic to be a swipe instead.

The swipe is same logic as shelf swipe but needs to be started on the
edge. Also moved tests to a new file.

Test: added tests
Bug: 497784
Change-Id: Id197d1109d39d89467d844d8b82c72f9a3547540
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2138552Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#757586}