Version: 52.0.2743.82 beta (64-bit)
OS: Ubuntu

What steps will reproduce the problem?
(1) Navigate to chrome://extensions.
(2) Install an extension that reloads itself in an infinite loop. Wait until Chrome blocks the extension from loading.

What is the expected output?
The "Warning: This extension reloaded itself too frequently." should be displayed in the box that corresponds to the installed extension.

What do you see instead?
No warning is displayed (unless the chrome:extensions page was refreshed).
Also, console logs show an unhandled exception:
"Error in event handler for developerPrivate.onItemStateChanged: Error: Assertion failed: Unreachable code hit", source: chrome://extensions-frame/ (0)


Debugging using Dev Tools showed that the exception is thrown in chrome.developerPrivate.onItemStateChanged event listener (source file chrome/browser/resources/extensions/extension_list.js) due to unexpected value of eventData.event_type ("WARNINGS_CHANGED").