Chrome Version: 68.0.3440.103
OS: Linux

What steps will reproduce the problem?
(1) Add a listener for requests via chrome.webRequest.onBeforeRequest
(2) Make an XHR request from a Google Chrome extension
(3) Look at the initiator field from the onBeforeRequest callback

What is the expected result?
The extension that initiated the request should be set as the initiator.

What happens instead?
The initiator field is not populated.