Starting from Chrome 72, certain request and response headers will not be available by default in webRequest listeners which specify ‘requestHeaders’ or ‘responseHeaders’ in the extraInfoSpec. To view, modify, or delete these headers, the listener will need to also specify ‘extraHeaders’ in the extraInfoSpec. The affected headers are:

Request headers:

• Accept-Language

• Accept-Encoding

• Cookie

• Referer

Response headers:

• Set-Cookie

Note: using ‘extraHeaders’ in a listener can impact performance for all matching requests, so only use this when absolutely necessary.

Thanks!