grass up vs roll on

grass up

verb
  • To betray by informing on. 

roll on

verb
  • To snitch or tattle (on a person or group), to reveal a secret under pressure, usually regarding criminal matters. 

  • To pass; to go on; to elapse. 

  • To continue to move forwards. 

intj
  • Used to express anticipation 

How often have the words grass up and roll on occurred in a corpus of books? (source: Google Ngram Viewer )