ccpr: Unregister path listeners when their cache entries are evicted

Bug: skia:8452
Change-Id: Ibd49d8f0ed15c568156c09db358eba0415df48f5
Reviewed-on: https://skia-review.googlesource.com/c/165120
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
3 files changed