cash in one's chips vs cross the river

cash in one's chips

verb
  • To die. 

  • To discontinue an activity, accepting whatever gains or losses one has incurred; to give up. 

cross the river

verb
  • Synonym of pass the river (to die) 

How often have the words cash in one's chips and cross the river occurred in a corpus of books? (source: Google Ngram Viewer )