Merge "Do not add duplicates to mWaitingVisibleActivities" into nyc-dev am: 697a3334
am: de914de

* commit 'de914de5f942ecf19bf4a2414f7203d256501871':
  Do not add duplicates to mWaitingVisibleActivities

Change-Id: I5a06f939a44ab47193ef14c449ff0aa543692289