DevTools: speedup console tests

The patch speeds up console tests which involve console.table commands.

BUG=377573
R=pfeldman

Review URL: https://codereview.chromium.org/307453003

git-svn-id: svn://svn.chromium.org/blink/trunk@174883 bbb929c8-8fbe-4397-9dbb-9b2b20218538