Please do paste the actual URL so we can look at language detection logs. (There's no way I'll be able to type that URL by hand :)

lol. sure thing:
https://namu.wiki/w/나무위키:대문

I found it from the cookbook for them-color toolbars :) 

Huh. We get no entry in the detection logs whatsoever. That probably means old and ugly state is still running around....

This is further supported that it only happens if I navigate to the page with network on, and then again when it's off. If I start Chrome w/ network off, I do not get a translate prompt. That means likely this was an in-page navigation.

Did you just refresh the URL, or did you navigate freshly?

Also: The correct fix here is probably to check net::NetworkChangeNotifier::IsOffline in TranslateManager::InitiateTranslation and early-out when things are offline.

I'd do that right at the top of InitiateTranslation, without recording any metrics - it's the equivalent of never requesting a translation.

WIP at https://codereview.chromium.org/1997573002

re: #3 
Yup. It was open in a tab, I turned on airplane mode, and then reloaded that tab. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0e7f1247be559c523607aa1452dfd2a351b85173

commit 0e7f1247be559c523607aa1452dfd2a351b85173
Author: groby <groby@chromium.org>
Date: Mon May 30 05:47:14 2016

[Translate] Don't try to translate when offline

If the user reloads a page during a network outage, and language
detection for this page has completed before, Chrome will currently
offer to translate that page, even though this cannot possibly succeed
when offline.

This CL adds an early-out for any attempts to translate content while
offline.

TEST=Load https://namu.wiki/w/나무위키:대문 - then turn off network. Hit reload. Observe translate is not offered a second time.

BUG= 612973 

Review-Url: https://codereview.chromium.org/1997573002
Cr-Commit-Position: refs/heads/master@{#396683}

[modify] https://crrev.com/0e7f1247be559c523607aa1452dfd2a351b85173/components/translate/core/browser/translate_manager.cc
[modify] https://crrev.com/0e7f1247be559c523607aa1452dfd2a351b85173/components/translate/core/browser/translate_manager_unittest.cc