Fix potential overflow in Visualizer effect am: 46dc714d52 am: 8720f85196 am: bad0250dcb am: 2feb9ce748 am: fba2bd1372 am: dddfa37ec9 am: de6acc18bb
am: a0f7a7b07e

Change-Id: I65c61bdb186ad6d83a94d1040d9266d2e08b2d64