WPT import https://crrev.com/c/1348256 introduced new failures in external/wpt/webrtc:

List of new failures:
external/wpt/webrtc/RTCRtpTransceiver.https.html new failing tests: https://crrev.com/c/1348256/4/third_party/WebKit/LayoutTests/external/wpt/webrtc/RTCRtpTransceiver.https-expected.txt
virtual/webrtc-wpt-unified-plan/external/wpt/webrtc/RTCRtpTransceiver.https.html [ Timeout ]

This import contains upstream changes from a89730a0f3638d709ccc42064c8f8eb8935b04f7 to 39e6009b920f632e6c2fee6cd3d96418d677d04f:
Automate one fullscreen test using `test_driver.bless` (#14072): https://github.com/web-platform-tests/wpt/commit/39e6009b920f632e6c2fee6cd3d96418d677d04f
Fix Feature Policy report output: https://github.com/web-platform-tests/wpt/commit/1832abd9419a532881abe413ef20e717ee8d2a3e
Merge pull request #14175 from jan-ivar/mergefix: https://github.com/web-platform-tests/wpt/commit/deaca4f1919bd2e44a708fce3a708e01e244da65
Fix bad merge 'Merge branch 'master' into gecko/1498793'.: https://github.com/web-platform-tests/wpt/commit/379c165e7c1d84d67fa1c53eb3c8c642566427f9 [affecting this directory]