DevTools: Fix tests broken by r172371

These test failures somehow failed to get caught by the try bots.

TBR=pfeldman

Review URL: https://codereview.chromium.org/249393002

git-svn-id: svn://svn.chromium.org/blink/trunk@172376 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Re-enable virtual/implsidepainting/inspector/timeline tests

BUG=298188
TBR=brianderson,pfeldman

Review URL: https://codereview.chromium.org/246253013

git-svn-id: svn://svn.chromium.org/blink/trunk@172377 bbb929c8-8fbe-4397-9dbb-9b2b20218538