[omnibox] Display last characters of user input when omnibox overflows.

Currently, when autocomplete text is longer than the omnibox width, the
user input is cropped completely. With this CL, the last 5 characters of
the user input will be displayed.

E.g., for omnibox width 10, user input "google.com/01", and suggestion
text "google.com/0123456789abcdef", the omnibox displays:
Previously: [23456789ab]
With this CL: om/01[23456]

This change is behind a flag.

Bug: 988569
Change-Id: I66b4f45bad30d0d77524080c42f73e79c4ee9eac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1723017
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682486}
2 files changed