[omnibox chrome:omnibox] Adjust default input values.

1) Default value for 'Current page classification' changed from
'new tab page omnibox' to 'arbitrary URL' because 'new tab page omniobx' won't
allow zero suggest results, but otherwise they act similarly.
2) 'Show all providers' checked by default.
3) The column 'Can be default' always visible instead of only when
'show all details' is checked.

Bug: 891303
Change-Id: Ic3bcd6a0f438485efa363135413929a8c85601cc
Reviewed-on: https://chromium-review.googlesource.com/c/1381145
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617608}
2 files changed