Revert of Unify filter-bar UI. (https://codereview.chromium.org/245183003/)

Reason for revert:
Makes timeline panel ugly.

Original issue's description:
> Unify filter-bar UI.
> 
> 1) Make test-filter padding consistent across all panels.
> 2) Add border between status- filter-bar and timeline panel.
> 
> BUG=347043
> NOTRY=true
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=172341

TBR=vsevik@chromium.org,eustas@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=347043

Review URL: https://codereview.chromium.org/249543002

git-svn-id: svn://svn.chromium.org/blink/trunk@172383 bbb929c8-8fbe-4397-9dbb-9b2b20218538