SkTHash: hash from fnptr to functor type

src/pdf/SkPDFCanon.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkPDFCanon_DEFINED
 #define SkPDFCanon_DEFINED
 
 #include "SkBitmap.h"
@@ skipping 84 matching lines @@
     SkTDArray<SkPDFImageShader*> fImageShaderRecords;
 
     struct WrapGS {
         explicit WrapGS(const SkPDFGraphicState* ptr = nullptr) : fPtr(ptr) {}
         const SkPDFGraphicState* fPtr;
         bool operator==(const WrapGS& rhs) const {
             SkASSERT(fPtr);
             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;
 
     SkTHashMap<SkBitmapKey, const SkImage*> fBitmapToImageMap;
     SkTHashMap<uint32_t /*ImageUniqueID*/, SkPDFObject*> fPDFBitmapMap;
 };
 #endif  // SkPDFCanon_DEFINED