SkTHash: hash from fnptr to functor type

src/pdf/SkPDFCanon.h

Index: src/pdf/SkPDFCanon.h
diff --git a/src/pdf/SkPDFCanon.h b/src/pdf/SkPDFCanon.h
index 988b2855e11404b0242e924cf809c05815d8af60..3d2ba6a77d1b4b2ea36023814c11080553e33e65 100644
--- a/src/pdf/SkPDFCanon.h
+++ b/src/pdf/SkPDFCanon.h
@@ -102,10 +102,12 @@ private:
             SkASSERT(rhs.fPtr);
             return *fPtr == *rhs.fPtr;
         }
-        static uint32_t Hash(const WrapGS& w) {
-            SkASSERT(w.fPtr);
-            return w.fPtr->hash();
-        }
+        struct Hash {
+            uint32_t operator()(const WrapGS& w) const {
+                SkASSERT(w.fPtr);
+                return w.fPtr->hash();
+            }
+        };
     };
     SkTHashSet<WrapGS, WrapGS::Hash> fGraphicStateRecords;