Opt in HTML Imports to UKM USeCounter

Bug: 766694, 523952
Change-Id: Ic794281024e97783d9f2bde6f2ca6c7f2eefdbb8
Reviewed-on: https://chromium-review.googlesource.com/1027551
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553909}
1 file changed