Retract GrSurfaceDrawContext.h a bit

This CL just pulls GrSurfaceDrawContext.h out of headers and .cpp files where possible.

TBR=brianosman@google.com
Bug: skia:11837
Change-Id: Ib96f3619e3a50091516f81ae48f956fe83c05aff
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/431384
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
34 files changed