Use SkTHashMap for the SkSL program-size checker.
Use SkTHashMap for the SkSL program-size checker.

Change-Id: Iae781edcd966393d6c1b43d79c7fb71705b8593d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/516456
Auto-Submit: John Stiles <f4fcf42d3bb5924557f1eeb3be66747535e585da@google.com>
Reviewed-by: Arman Uguray <b18dd57f0c81bc1fc439e303e71d2866b09f3bd2@google.com>
Commit-Queue: Arman Uguray <b18dd57f0c81bc1fc439e303e71d2866b09f3bd2@google.com>

google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia