Move caps and FP factory cache to GrContext_Base

Both GrContext and GrContextThreadSafeProxy had their own copies. This centralizes ownership and standardizes how all the contexts get initialized.

Change-Id: Ib2e418fbb53fcd6b0054789ef30a5fc4a3d80b20
Reviewed-on: https://skia-review.googlesource.com/c/189305
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
14 files changed