Gardening: inspector/timeline/timeline-bound-function.html flakily times out

BUG=419566
TBR=eustas@chromium.org,pfeldman@chromium.org

Review URL: https://codereview.chromium.org/622023002

git-svn-id: svn://svn.chromium.org/blink/trunk@183099 bbb929c8-8fbe-4397-9dbb-9b2b20218538