Try finding exact scratch texture in cache before approx

Bug: skia:
Change-Id: Ia65b94bde7aa52e951ba94a0012e794f02c3177e
Reviewed-on: https://skia-review.googlesource.com/42940
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
1 file changed