Try making pop_back_n faster

Change-Id: I17eedcd9e29c45e7109d27c95d588f46848971fe
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/607047
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
1 file changed