Move GrOp::VisitProxyFunc to GrTypesPriv.h GrVisitProxyFunc

This is almost purely a query/replace CL (% the #include juggling).
The VisitProxyFunc is used by more than just the Ops and will probably
still be required in the NGA.

This is a prelude to making all the remaining GrOp-derived classes OGA-only.

Bug: skia:11837
Change-Id: If1c127e5c126c676be529ed2a61dd7953abb03d0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/419162
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrTextureResolveRenderTask.cpp b/src/gpu/GrTextureResolveRenderTask.cpp
index fd13d65..f079994 100644
--- a/src/gpu/GrTextureResolveRenderTask.cpp
+++ b/src/gpu/GrTextureResolveRenderTask.cpp
@@ -91,5 +91,5 @@
 }
 
 #ifdef SK_DEBUG
-void GrTextureResolveRenderTask::visitProxies_debugOnly(const GrOp::VisitProxyFunc& fn) const {}
+void GrTextureResolveRenderTask::visitProxies_debugOnly(const GrVisitProxyFunc&) const {}
 #endif