Tests Page.frameStartedLoading / Page.frameStoppedLoading events with  different kinds of frame navigation
Initial navigation
main target: Page.frameStartedLoading
main target: Page.frameStoppedLoading
Navigating same origin
main target: Page.frameStartedLoading
main target: Page.frameStoppedLoading
Navigating cross origin
main target: Page.frameStartedLoading
child target: Page.frameStoppedLoading
http://oopif-a.devtools.test:8000/inspector-protocol/resources/empty.html
Navigating cross origin again
child target: Page.frameStartedLoading
child target: Page.frameStoppedLoading
http://oopif-b.devtools.test:8000/inspector-protocol/resources/empty.html
Navigating back to in-process
child target: Page.frameStartedLoading
main target: Page.frameStoppedLoading
Navigating main frame to same origin
main target: Page.frameStartedLoading
main target: Page.frameStoppedLoading
Navigating main frame cross-process
main target: Page.frameStartedLoading
main target: Page.frameStoppedLoading