GitLab

Proto change copied from cl/176384092. This CL expand the
"has_user_gesture" boolean field into a enum to include
more information on how the navigation happens.
Tests updated accordingly.

Bug: 780532
Change-Id: Ic13d8472aa6ea3e42f268f92bf46c6cae64f4066
Reviewed-on: https://chromium-review.googlesource.com/802185
Commit-Queue: Jialiu Lin <jialiul@chromium.org>
Reviewed-by: Luke Z <lpz@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524157}