[chrome:omnibox] Add styling to table headers.

Currently, to help distinguish contents of multi-property cells, we apply
different styling to each property value. To further clarify which value is
associated with which property, this CL applies similar styling to their
headers. E.g., currently, provider names are displayed in green, and provider
types are displayed in black. This CL similarly styles the header text:
'[green]Provider[/green] & Text'.

Bug: 891303
Change-Id: I79249000ed401c918497f1f6007757cb2202c905
Reviewed-on: https://chromium-review.googlesource.com/c/1374528
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617544}
2 files changed