SkSL: Reduce default heap usage, improve heap benchmarks

We were always pre-loading the fragment and vertex modules, but deferred
loading all others. Those two take up about 300 KB of heap. Now, all
modules are deferred, so compiler instances that don't need them (like
the one used for runtime effects) are much smaller.

Now that we can get better fine-grained numbers, added two more
benchmarks, to track actual baseline usage, plus the usage in the two
most likely configurations.

Change-Id: Idfbcd52c8afee566ac42ab827c80c940f91c4ad7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/337176
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
3 files changed