Tests that XMLHttpRequest Logging works when Enabled and doesn't show logs when Disabled for asynchronous XHRs.
Bug 79229
-XHR finished loading: GET "http://127.0.0.1:8000/inspector/resources/xhr-exists.html". network-test.js:97
+XHR finished loading: GET "http://127.0.0.1:8000/inspector/resources/xhr-exists.html". network-test.js:101
XHR loaded: 1 network-test.js:6
XHR loaded: 2 network-test.js:6