The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/eccfdf3b662e3d964fe96ebd71aea4f71beb1947

commit eccfdf3b662e3d964fe96ebd71aea4f71beb1947
Author: Jennifer Apacible <japacible@gmail.com>
Date: Tue Sep 11 22:43:41 2018

[Picture in Picture] Show controls on mouseover on the window.

The controls sometimes disappear depending on the mouse interactions
with the window. For example, when the controls disappear automatically,
the controls should reappear when the user moves around the window.

Bug:  882615 
Change-Id: Ic4c0a391d81ec6ea475d19be6cd60b40cb0ba277
Reviewed-on: https://chromium-review.googlesource.com/1217719
Commit-Queue: apacible <apacible@chromium.org>
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590512}
[modify] https://crrev.com/eccfdf3b662e3d964fe96ebd71aea4f71beb1947/chrome/browser/ui/views/overlay/overlay_window_views.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/47544a007561b82f8c428860e93d79f507326fd5

commit 47544a007561b82f8c428860e93d79f507326fd5
Author: Jennifer Apacible <japacible@gmail.com>
Date: Tue Oct 23 16:01:41 2018

[Picture in Picture] Show controls on mouseover on the window.

The controls sometimes disappear depending on the mouse interactions
with the window. For example, when the controls disappear automatically,
the controls should reappear when the user moves around the window.

Bug:  882615 
Change-Id: Ic4c0a391d81ec6ea475d19be6cd60b40cb0ba277
Reviewed-on: https://chromium-review.googlesource.com/1217719
Commit-Queue: apacible <apacible@chromium.org>
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#590512}(cherry picked from commit eccfdf3b662e3d964fe96ebd71aea4f71beb1947)
Reviewed-on: https://chromium-review.googlesource.com/c/1296820
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/branch-heads/3538@{#1036}
Cr-Branched-From: 79f7c91a2b2a2932cd447fa6f865cb6662fa8fa6-refs/heads/master@{#587811}
[modify] https://crrev.com/47544a007561b82f8c428860e93d79f507326fd5/chrome/browser/ui/views/overlay/overlay_window_views.cc

Here's a summary of the rules that were executed: 
 - OnlyMergeApprovedChange: Rule Failed -- Revision 47544a007561b82f8c428860e93d79f507326fd5 was merged to refs/branch-heads/3538 branch with no merge approval from a TPM! 
Please explain why this change was merged to the branch!
 - AcknowledgeMerge: Notification Required -- 

The following revision refers to this bug: 
https://chromium.googlesource.com/chromium/src.git/+/47544a007561b82f8c428860e93d79f507326fd5

Commit: 47544a007561b82f8c428860e93d79f507326fd5
Author: japacible@gmail.com
Commiter: beccahughes@chromium.org
Date: 2018-10-23 16:01:41 +0000 UTC

[Picture in Picture] Show controls on mouseover on the window.

The controls sometimes disappear depending on the mouse interactions
with the window. For example, when the controls disappear automatically,
the controls should reappear when the user moves around the window.

Bug:  882615 
Change-Id: Ic4c0a391d81ec6ea475d19be6cd60b40cb0ba277
Reviewed-on: https://chromium-review.googlesource.com/1217719
Commit-Queue: apacible <apacible@chromium.org>
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#590512}(cherry picked from commit eccfdf3b662e3d964fe96ebd71aea4f71beb1947)
Reviewed-on: https://chromium-review.googlesource.com/c/1296820
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/branch-heads/3538@{#1036}
Cr-Branched-From: 79f7c91a2b2a2932cd447fa6f865cb6662fa8fa6-refs/heads/master@{#587811}

Tried testing the issue on win-10 and mac 10.13.3 using chrome build without fix #71.0.3548.0 as per comment #8 of issue id: 897246. Observed that the issue did not reproduce on win-10 i.e controls appeared everytime when the mouse moved around the pip window as in the attached screen cast whereas the issue reproduced on mac 10.13.3 i.e controls did not display on the PiP window.

beccahughes@/lethalantidote@ - Could anyone please let us know if the issue is specific to os-Mac or there are any other steps to reproduce the issue.
Note: ccing the reviewers of the issue as the author's chromium id is inactive.

Thanks...!!

Deleted: 882615@win-10_buildwithoutfix.mp4 4.2 MB

	882615@win-10_buildwithoutfix.mp4 4.2 MB View Download

This fix was specific to non-windows platforms. This has already been verified in https://crbug.com/897246

beccahughes@, thank you for the quick confirmation.