WPT import https://crrev.com/c/1053830 introduced new failures in external/wpt/infrastructure:

List of new failures:
external/wpt/infrastructure/expected-fail/timeout.html [ Timeout ]

This import contains upstream changes from 9ae71f6f84af552ad85bf5a10327c74a4b1df2ef to a1b510cb7b823d741a5edf39d5fd510cf002abe8:
Add a test that should timeout to the infrastructure tests: https://github.com/w3c/web-platform-tests/commit/a1b510cb7b823d741a5edf39d5fd510cf002abe8 [affecting this directory]
Complete the migration from marionette-specific scripts.: https://github.com/w3c/web-platform-tests/commit/fce59968b2e620b098536c05c5409f7f6f6e4b66
wdspec] Align formatting of custom delete cookie command. bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1457054 gecko-commit: 2e0af0221a8ea76a9445c51e9f86b025766e7721 gecko-integration-branch: autoland gecko-reviewers: automatedtester: https://github.com/w3c/web-platform-tests/commit/3e9db73326de324c3436e03c185fc0c5746e4dc1
wdspec] Remove unwanted docstrings with reference to the spec. bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1457054 gecko-commit: 149859d8a23d280e1e8b62ce9747dbbf71e18a85 gecko-integration-branch: autoland gecko-reviewers: automatedtester: https://github.com/w3c/web-platform-tests/commit/43e316876f3284536c7c885cdb196cbb3cc97d2c
wdspec] Use correct assertions for delete cookie tests. bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1457054 gecko-commit: ab7307312bb7ded67672b9d8cb2ec723dea1f23d gecko-integration-branch: autoland gecko-reviewers: automatedtester: https://github.com/w3c/web-platform-tests/commit/a81b04ecb66bfec4d86440dda55323ec0c187c33