I am seeing this as well on Fedora 24. Anything past version 56 locks the entire UI when an alert box is shown (eg. https://jsfiddle.net/dotnetcodecentral/82wmN/).

I believe this is related to the same problem behind  issue #533885 . If the alert(1) fires when Chrome is on the High-DPI laptop screen it works fine. If I drag Chrome to the Low-DPI attached monitor and open that link the UI freezes.

 Issue #533885  has been annoying and it's surprising it's still open, but with the alert(1) issue Chrome is now not usable after version 56.

Unable to reproduce the scenario on Ubuntu 14.04 with chrome #58.0.3029.81 with the provided url in the comment #2

Didn't observe the any unresponsiveness on clicking the alert box

Attaching the screen-cast for reference.

Deleted: Issue 712996.mp4 1.5 MB

	Issue 712996.mp4 1.5 MB View Download

Including a screencast of reproducing this behavior in 58.0.3029.81-1 on Fedora 24. The screencast includes both monitors and shows how it works on the left (3840x2160) screen but not when dragged to the right (1920x1080) monitor. When on the right side the alert does not appear and the tab appears to be continuously loading. Closing the full browser is the only option.

I apologize, the screencast tends to flash a bit.

Deleted: chrome-dpi-alerts.mp4 7.6 MB

	chrome-dpi-alerts.mp4 7.6 MB View Download

Turns out the UI keeps responding to the keyboard. So if I press Space to click the highlighted OK button on the dialog box, everything returns to normal. So it seems like all that's happening is a failure to show the dialog box.

Thank you for providing more feedback. Adding requester "kkaluri@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Unable to reproduce this issue on Ubuntu 14.04 with chrome #58.0.3029.96 with dual monitor setup, didn't observe any responsiveness in any monitors while accessing the url in comment #2.

Adding "TE-NeedsTriageFromMTV" label for further triage on fedora multi monitor setup.

Thank You... 

kkaluri: Can you try reproing with the commandline flag --disable-features=AutoDismissingDialogs ? If you can repro with it, this is likely a dup of bug 709685.

kkaluri Can you include the resolutions of the monitors you were testing with?

I'm on version 60.0.3112.78 now and this no longer seems to be an issue.

For anyone affected by this issue: is this fixed on the latest dev release (68.0.3440.15 or later)?

Does this still repro?

Closing due to lack of feedback.