DevTools: unskip console-viewport-selection.html

The inspector/console/console-viewport-selection.html test is finally
green.

BUG=390204
TBR=vsevik

Review URL: https://codereview.chromium.org/500583003

git-svn-id: svn://svn.chromium.org/blink/trunk@180913 bbb929c8-8fbe-4397-9dbb-9b2b20218538