Remove VisitorType from GrOp::visitProxies

We are planning to start detecting mipmaps and MSAA resolves during
the "gather" step now, so all visits should behave the same at this
point. (And it appears there might not have been any GrOps that
actually changed their behavior based on this flag at the moment.)

Bug: skia:
Change-Id: I7a7a1c9c47cbe03683c42025bf6d0ecb32a57ba1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215145
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/GrRenderTargetOpList.h b/src/gpu/GrRenderTargetOpList.h
index 2eec472..475c088 100644
--- a/src/gpu/GrRenderTargetOpList.h
+++ b/src/gpu/GrRenderTargetOpList.h
@@ -155,7 +155,7 @@
             SkASSERT(fList.empty());
         }
 
-        void visitProxies(const GrOp::VisitProxyFunc&, GrOp::VisitorType) const;
+        void visitProxies(const GrOp::VisitProxyFunc&) const;
 
         GrOp* head() const { return fList.head(); }