Chrome Version: 57.0.2987.8 dev
OS: Ubuntu 14.04

What steps will reproduce the problem?
(1)Launch chrome and sign in to user >> Create/Import supervised user
(2)Go to main user and select exit and childlock >> Now on user manager window click on main user so that re-authentication dialog appears
(3)Left mouse click on maximise button and then again right mouse click on maximise button and observe[Please refer video]

Expected: Authentication dialog should be maximised and should be able to close.
Actual: Instead after maximising unable to close authentication dialog and unable to use user manager window.

This is Non-regression issue seen from introduction of authentication for parent profile in M53.

Issue is not seen in windows
 

Deleted: Actual_supervised.ogv 3.3 MB

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