Plumb initiator origin in Java for clank popup handling.

As of https://crrev.com/617708 the expectation is that all renderer
initiated navigations must specify the origin of the document that
started the navigation.

This CL adds initiator origin serialization into Java and back into
C++ to allow Clank popup handling to supply the initiator origin for
renderer-initiated navigations.

Bug: 882053
Change-Id: I416ec4ad7b8fd20679c107aa67f45ed6b4c9e023
Reviewed-on: https://chromium-review.googlesource.com/c/1396838
Commit-Queue: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620155}
5 files changed