Gardening: widen expectation for inspector/console/console-viewport-selection.html

Flaky on all platforms.

BUG=390204
TBR=lushnikov

Review URL: https://codereview.chromium.org/389253003

git-svn-id: svn://svn.chromium.org/blink/trunk@178028 bbb929c8-8fbe-4397-9dbb-9b2b20218538