[chrome:omnibox] Display string representation for transition column enum.

Previously, the transition column displays the enum's integer representation.
The 'generated' and 'typed' transition values are most common, adjusting the
transition column width to 70px (from 60px) allows these values to be displayed
without eliding.

Bug: 891303
Change-Id: Ic356e9f89541e22fa1cdfd54959a444d0cab6836
Reviewed-on: https://chromium-review.googlesource.com/c/1374489
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616092}
3 files changed