Move "matches" from GrContextThreadSafeProxy to GrContext_Base

This makes the "matches" functionality available to all the context flavors and uses it for SkImages

Change-Id: I1e3d55f19a7752a9da8789e93a848b7a7a64d180
Reviewed-on: https://skia-review.googlesource.com/c/190227
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
15 files changed