The time returned by performance-now, which was used in componentDidMount and componentWillReceiveProps lifecycle functions to reset the animation, can be greater than the timestamp of requestAnimationFrame (raf) callback. Thus we got negative values for timeDelta. By initializing and resetting prevTime with null instead and setting it to to the timestamp of the first requestAnimationFrame callback, we can prevent negative values.
The time returned by performance-now, which was used in
componentDidMountandcomponentWillReceivePropslifecycle functions to reset the animation, can be greater than the timestamp ofrequestAnimationFrame(raf) callback. Thus we got negative values fortimeDelta. By initializing and resettingprevTimewith null instead and setting it to to the timestamp of the firstrequestAnimationFramecallback, we can prevent negative values.fixes #453