Add Clang GPU tasks.

No-Try: true
Change-Id: I5290942396a903fcaac94feaab83a5db31af1f93
Reviewed-on: https://skia-review.googlesource.com/45844
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
2 files changed