Move default init of tmp draw params out of subclasses into GrGpu

I want to move srgb conversion logic to GrGpu from subclasses and I think it will make more sense if the temp draw info is fully initialized before invoking the subclass.

Change-Id: Icfc4d564fc0d3c7c12f78c77f5ea921d979e290d
Reviewed-on: https://skia-review.googlesource.com/106260
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
3 files changed