Never happened to me on the S5 yet but it happened for me some times on the nexus 7 2014 while using chrome (only on kitkat). Guess its a general problem that can happen in android since KitKat. Hope google can fix it asap.
Current device: Black Samsung Galaxy S5 GM-900F
Previous: Black mist Samsung Galaxy S4 i9500 and Pebble blue Samsung Galaxy S3 I9300.