Allow tracking of Precompositions onEnter/onExit

Change-Id: I065288b212d8ffc4d0ca127940e524799f59aff7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/454976
Reviewed-by: Avinash Parchuri <aparchur@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Avinash Parchuri <aparchur@google.com>
2 files changed