Change origin.mojom to use url::Origin::Nonce for serializing opaque origins.

This CL is part of adding precursor origin support to url::Origin which
nick@ started in https://crrev.com/c/1028985. It changes the Mojo
representation of url::Origin to use the nonce as an indicator for
whether the origin is opaque or not instead of keeping a boolean.

Bug: 882053
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: If260a09a66cf62b870f15d52f5aabc27a3f73823
Reviewed-on: https://chromium-review.googlesource.com/1227393
Commit-Queue: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594911}
9 files changed