Mark another test as flaky.
Mark another test as flaky.

TBR=pfeldman
BUG=240400

Review URL: https://codereview.chromium.org/15077009

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@150251 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