Only way for reset 'Proxy Negotiation' time, its full reopen chrome.

I just crash main process and reopen.

@Reporter: Could you please provide a sample extension which makes 
requests with Proxy, in order to triage in a better way.

Thanks!

Is the extension acting as the proxy, or is it just making requests to the proxy? Do other non-extension requests function correctly?

Can you provide a net-internals of when the proxy negotiation is slow.

See instructions:
https://dev.chromium.org/for-testers/providing-network-details

Ping -- please provide the information requested in comment #5...

Thank you for providing more feedback. Adding requester "vamshi.kommuri@techmahindra.com" to the cc list and removing "Needs-Feedback" label.

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

1 moment, before each request starting, PAC updating with new proxy for site. Its was only way for my project works well.

@Reporter: Could you please check on the latest chrome stable #66.0.3359.181. if this issue still persists/not.Request someone from the network team for help in investigation of the attached log in C#7.

The log shows us a 200-600 millisecond delay on each request between sending the request and getting a response.  Digging into it, during that delay we're just waiting on the network - write data to the socket, wait, then hear back.  We always either have an old socket to reuse, or setting up a connection through the proxy takes only a couple milliseconds - that wait for a response is the only major delay.  It's also not an SSL issue, since the delay is seen at the layer below that.

Conclusion:  We're waiting on either the proxy or the site its talking to to response.  This doesn't look like a Chrome issue.  IF you don't see these delays without the proxy, it's likely a bug in the proxy itself.

There are other problems in your setup.

The extension appears to be changing the proxy settings continually ever few hundred ms, by setting a PAC script that redirects traffic for *opskins.com to a proxy (and there is also an attempt at checking proxy auto-detect).

My guess is that this was an attempt at load balancing between possible proxy servers? This is not a good way to do it, as it is likely to lead to bad performance. Re-setting the PAC script so frequently has CPU overhead. Even worse, you end up with lots of duplicated sessions to the target server split across lots of proxy servers, which negates performance benefits of http2 session re-use, puts more load on the server, etc.

Are you the maintainer of the extension (Doesn't seem to be available publicly)?
A better approach for the extension would be to set the PAC script infrequently (or once), and do the load balancing internally. For instance, it can modulate which proxy server to use based on Date.now().

An even better approach would be to not use so many different proxy servers.

Closing as WontFix since this seems like a problem on the user's environment (proxy setup / proxy servers).