Unflake inspector/console/console-format-es6.html

BUG=432907
TBR=pfeldman

Review URL: https://codereview.chromium.org/723903004

git-svn-id: svn://svn.chromium.org/blink/trunk@185356 bbb929c8-8fbe-4397-9dbb-9b2b20218538