[OnionSoup] Replace blink::ReferrerPolicy with network::mojom::ReferrerPolicy

This CL tries to unify the definition of referrer policy enum, removing
blink::ReferrerPolicy by replacing it with
network::mojom::ReferrerPolicy everywhere inside Blink.

BUG=860403

Change-Id: Ia14a116facf2f8a1901a9c8ea6e4fdc960aa6ae5
Reviewed-on: https://chromium-review.googlesource.com/c/1347779
Commit-Queue: Leon Han <leon.han@intel.com>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611587}
102 files changed