Chrome Version:52.0.2723.0 (Official Build)Revision 5e216d9b62275101c30f4a5cb2174bb68970ef3c-refs/heads/master@{#391139}  (64-bit) 
OS: Mac OSX(10.10.5, 10.11.4)

Precondition: Install the 'chrome-app-samples-master' folder from https://github.com/GoogleChrome/chrome-app-samples

What steps will reproduce the problem?
1.Launch chrome and navigate to chrome://extensions,Tick 'developer mode' checkbox.
2.Click on 'load unpacked extension', select 'chrome-app-samples-master' folder and Install "clock" V2 apps
3.Click on permission link button from chrome://extensions such that dialog box appears, click fullscreen icon from top left.
4.Now hover mouse to toggle out and observe.

Actual: Tabstrip is not displayed to toggle browser window out of fullscreen mode.

Expected:  Tabstrip should be displayed to toggle browser window out of fullscreen mode.

This is a regression issue broken in 'M52' and will soon update other info.