UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

Steps to reproduce the problem:
I do a web extension that reports when HTTP 2 is used for a request. I gather page information with

chrome.webRequest.onCompleted.addListener(
(function(details){console.log(details)})

On web servers that do use HTTP2, I get this:

frameId: 0
fromCache: false
ip: "216.58.206.228"
method: "GET"
parentFrameId: -1
requestId: "7088"
responseHeaders: (21) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}]
statusCode: 200
statusLine: "HTTP/1.1 200"
tabId: 43
timeStamp: 1545322995560.8499
type: "main_frame"
url: "https://www.google.com/search?q=crbug&rlz=1C1CHBF_frFR793FR793&oq=crbug&aqs=chrome.0.69i59j0l2j5l2.1207j0j7&sourceid=chrome&ie=UTF-8"
__proto__: Object

Note that the statusLine property is "HTTP/1.1 200" while it should be "HTTP/2.0 200 OK"
- The Chrome dev tools "Protocol" column does display "h2" on any page I tested
- Firefox reports the statusLine as expected

What is the expected behavior?
The statusLine property of the "details" object should be "HTTP/2.0 200 OK"

What went wrong?
I don't know. You can test this on any property with HTTP2, including Google.com or even https://bugs.chromium.org

Alternatively, is there any other way to detect HTTP2 protocol for a given page load?

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 71.0.3578.98  Channel: stable
OS Version: 10.0
Flash Version: