Revert "Revert "added support for sk_Dimensions to SkSL""

This reverts commit e6ab998bc2e675ab0a426ec9434be887e5527ab3.

Bug: skia:
Change-Id: I19451f924d514dadac9d2c326bcc8404a1b501e9
Reviewed-on: https://skia-review.googlesource.com/149239
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
17 files changed