Tests fetch interceptor respects cross-frame boundaries of out-of-process iframes.

Loading in-process iframe (script should be present)
Request to http://127.0.0.1:8000/inspector-protocol/fetch/resources/frame-with-subresource.html, type: Document
Request to http://127.0.0.1:8000/inspector-protocol/resources/dummy.js, type: Script

Loading out-of-process iframe (script should be absent)
Request to http://devtools.oopif-a.test:8000/inspector-protocol/fetch/resources/frame-with-subresource.html, type: Document

Loading out-of-process iframe with interception (script should be present)
Request to http://devtools.oopif-a.test:8000/inspector-protocol/fetch/resources/frame-with-subresource.html, type: Document
[subframe] Request to http://devtools.oopif-a.test:8000/inspector-protocol/resources/dummy.js, type: Script