The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fcecf03e2a0f4c0105dbf877786c16b95fb73a1e

commit fcecf03e2a0f4c0105dbf877786c16b95fb73a1e
Author: Jennifer Apacible <apacible@chromium.org>
Date: Wed Aug 29 00:36:48 2018

[Picture in Picture] Auto-hide controls after 2.5s after user tap.

Currently, gesture interactions (tap) shows the controls, but they only
disappear if the user taps outside of the window to blur. There is no
other way of "hiding" the controls similar to using a mouse to no
longer hover over the window.

This change hides the controls automatically after 2.5 seconds. Every
time the user taps on the window, the 2.5s is reset. If there is some
other user gesture (e.g. mouse hover), the timer is stopped.

Bug:  878083 
Change-Id: I9d3a4b28b92e495960ac98eb9a9fcf9a1103bfb6
Reviewed-on: https://chromium-review.googlesource.com/1192358
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Commit-Queue: apacible <apacible@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586965}
[modify] https://crrev.com/fcecf03e2a0f4c0105dbf877786c16b95fb73a1e/chrome/browser/ui/views/overlay/overlay_window_views.cc
[modify] https://crrev.com/fcecf03e2a0f4c0105dbf877786c16b95fb73a1e/chrome/browser/ui/views/overlay/overlay_window_views.h

@Jennifer Apacible: As we are not very clear about the test steps, could you please help us in providing the test steps required along with any test file(...if applicable) and help us in verifying the fix.

Thanks!