The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9d6f39a010b60dfa489615b80379f502421ea231

commit 9d6f39a010b60dfa489615b80379f502421ea231
Author: sawtelle <sawtelle@google.com>
Date: Wed Aug 15 16:10:17 2018

[Picture in Picture] Show custom controls on PiP window

Currently, assigning custom controls to a video through a call to
setPictureInPictureCustomControls() passes in the data but does not
show the buttons on the PiP window. This CL makes it so that up to 2
buttons are added to the PiP window on the left and the right of the
play/pause button when this call is made.

Note: the desired icon that is passed in is not currently being
assigned to these new buttons, and they are currently using the play
and pause icons as defaults, for left and right respectively. This
will be updated to work properly in a future patch - this is just to
get the basic functionality set up.

Bug:  864271 
Change-Id: I42d9cf47dcd22dd481675b1990e1bb9ae2265055
Reviewed-on: https://chromium-review.googlesource.com/1139110
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: apacible <apacible@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583270}
[modify] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/picture_in_picture/picture_in_picture_window_controller_browsertest.cc
[modify] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/ui/BUILD.gn
[add] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/ui/views/overlay/control_image_button.cc
[add] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/ui/views/overlay/control_image_button.h
[modify] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/ui/views/overlay/overlay_window_views.cc
[modify] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/browser/ui/views/overlay/overlay_window_views.h
[add] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/test/data/media/picture-in-picture/icon.png
[modify] https://crrev.com/9d6f39a010b60dfa489615b80379f502421ea231/chrome/test/data/media/picture-in-picture/window-size.html