webRequest.onCompleted issue with FF57

Hi there, I noticed an issue with my extension after upgrade to FF57. Basically it uses a callback on webRequest.onCompleted to track the status codes of responses and in case of errors communicate them to page_action to notify the user. The callback placed in background script. Until the upgrade all the requests from a tab to the tab’s url has been reported with details.tabId correctly set to the actual tab’s identifier. After the upgrade all values I see details.tabId are “-1”.

The documentation states, that “-1” is set for requests which are not related to any tab, but in this case I have “-1” for the HTTP requests to the urls from the url bar and I can hardly see how they can be not related to a tab.

I this change something expected and I should a different approach to connect a request to a tab id (like url matching), or this is simply a bug?