Revert of DevTools: remove exuberant overflow:hidden (https://codereview.chromium.org/282553002/)

Reason for revert:
Sortable columns in DataGrid are regressed.

Original issue's description:
> DevTools: remove exuberant overflow:hidden
> 
> This makes NetworkPanel much faster.
> 
> BUG=372246
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=174080

TBR=pfeldman@chromium.org,apavlov@chromium.org,aandrey@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=372246

Review URL: https://codereview.chromium.org/289983005

git-svn-id: svn://svn.chromium.org/blink/trunk@174082 bbb929c8-8fbe-4397-9dbb-9b2b20218538