Hilary Duff's 'teased' a "little secret" (we imagine it's a new song) featuring input from 'quite good' songwriting trio Savan Kotecha, Carl Falk and Kristian Lundin.
The 'teasing' happened via the medium of Twitter in the following manner:
“Can’t wait for everyone to hear our little secret…@savan_kotecha @carlfalkmusic @kristian_lundin”
— Hilary Duff (@HilaryDuff) August 7, 2014
Perhaps 'Chasing The Sun' was (/has become) just one of those 'buzz track' things people do.