Add flaky line for editing/selection/4960116.html.
Add flaky line for editing/selection/4960116.html.

tbr/notry since this is killing the commit queue.

TBR=tkent@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/246753005

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@172280 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs