Chrome Version : 73.0.3660.0 (Official Build) 170f55273fbe689f402eade1a4e98fa2788938a2-refs/branch-heads/3660@{#1} 64 bit
OS : Mac(10.13.6, 10.13.1, 10.14.3)

What steps will reproduce the problem?
1. Launch chrome, open chrome://apps page, right click on 'Web Store' icon and check 'Open as a Window' option.
2. Launch 'Web Store', select any app from store and click on 'Add to Chrome' button.
3. Observe the 'Add app' confirmation dialog box. 

Actual Result : 'Add app' confirmation dialog box is seen misplaced.

Expected Result : 'Add app' confirmation dialog box should open at it's proper position.

This is a regression issue broken in M-73 and below is the bisect information:
Good Build : 73.0.3640.0 (Revision : 616532)
Bad Build : 73.0.3641.0 (Revision : 616888)

Chromium bisect URL:
https://chromium.googlesource.com/chromium/src/+log/c5454142857d5d2e166133d5dbaf3a803301f663..bbfa243d61bb12cb6f21781ed85345004b5c9362

Suspecting: r616794 ?

@Christopher : Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Note : 
1. Unable to provide bisect using per-revision script as it shows an error message.
2. Tried on other machines but still getting the same error again.
3. Hence provided suspect through 'Chromium bisect'.
4. Issue is not reproducible in Windows (7,8,10) and Linux(14.04 LTS) OS

Thank you..!
 

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