Add a benchmark that measures SkSL::Compiler startup time

This is basically timing the rehydrator, but is helpful in conjunction
with heap usage if a client wants to decide to throw away a compiler
that they don't anticipate using for some amount of time.

Change-Id: Ie9b27d9a3b7667b5492d870f242cdafd00784708
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/320617
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
1 file changed