GitLab

Read the attribute based on the origin trial being enabled otherwise
even if it wasn't the attribute would get set on the navigation param.
In the same branch count the usage as this will be useful for the origin
trial.

BUG=872777

Change-Id: I1cc4eeba4051cf45c65e54f7dad02ec1114ecb1a
Reviewed-on: https://chromium-review.googlesource.com/c/1334198
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608039}