Deflake LayoutTests/inspector/timeline/timeline-layout-autosize.html

TBR=enne,pfeldman

Apparently, it became flaky after r168232.

Review URL: https://codereview.chromium.org/176933003

git-svn-id: svn://svn.chromium.org/blink/trunk@168288 bbb929c8-8fbe-4397-9dbb-9b2b20218538