Tests that multiple HTTP headers with same name are correctly folded into one LF-separated line.
Pragma header of fetch of http://127.0.0.1:8000/inspector-protocol/network/resources/multiple-headers.php?fetch=1:
Network.responseReceived: value1, value2
Network.responseReceivedExtraInfo: value1
value2
Pragma header of navigation to http://127.0.0.1:8000/inspector-protocol/network/resources/multiple-headers.php:
Network.responseReceived: value1
value2
Network.responseReceivedExtraInfo: value1
value2