Chrome Version: <From about:version: Google Chrome 57.0.2987.32>
Chrome OS Version: <From about:version: Platform 9202.18.0>
Chrome OS Platform: <Kefka/Samus>
Network info: <WiFi>

Please specify Cr-* of the system to which this bug/feature applies (add
the label below).

Steps To Reproduce:
(1) Connect to network that is configured to use an auth-proxy. 
(2) When browsing, the Proxy Authentication dialog pops up, enter User Name and Password 
(3) Remove the network from preferred list. 
(4) Connect  to same network  and configure auth-proxy again.

Expected Result:
Proxy authentication dialog should pop up again. 

Actual Result:
No Proxy authentication dialog

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
Always

What is the impact to the user, and is there a workaround? If so, what is
it?

Please provide any additional information below. Attach a screen shot or
log if possible.
Logs attached. 

For graphics-related bugs, please copy/paste the contents of the about:gpu
page at the end of this report.

Will update, if I see this issue in R56 and R55. 
 

Deleted: log-020717-155354.tar.gz 1.3 MB

log-020717-155354.tar.gz 1.3 MB Download