Add GPUSink getters to suppress unused field warnings in no gpu build.

Change-Id: Iab66cf3a8fd1d3008f62d832cdb7f9a65b2077f7
Reviewed-on: https://skia-review.googlesource.com/113420
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed