Chrome Version: 68.0.3440.118
Chrome OS Version: 10718.88.2
Chrome OS Platform: asus 
Network info: does not matter

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

Steps To Reproduce:
(1) Create a chrome app with a background page
(2) Create a udp socket in background page
(3) Send a packet to multicast address (224.0.0.251)
(4) Have a process on another machine send unicast response directly to socket on background page


Expected Result:

Socket on background page receives the unicast response 

Actual Result:

Socket on backround page never receives the unicast response

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?

Our app is print provider plugin.  Because of this, user never sees any printers.

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

This is a regression, as this code used to work on an older version of Chrome OS. We think sometime in the past 30-60 days there was an update that caused this problem.

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