Refactor SkGrFontScaler and SkGrFontKey into non-virtual versions.

include/gpu/GrKey.h

-/*
- * Copyright 2010 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrKey_DEFINED
-#define GrKey_DEFINED
-
-class GrKey : public SkRefCnt {
-public:
-    SK_DECLARE_INST_COUNT(GrKey)
-
-    typedef intptr_t Hash;
-
-    explicit GrKey(Hash hash) : fHash(hash) {}
-
-    intptr_t getHash() const { return fHash; }
-
-    bool operator<(const GrKey& rh) const {
-        return fHash < rh.fHash || (fHash == rh.fHash && this->lt(rh));
-    }
-    bool operator==(const GrKey& rh) const {
-        return fHash == rh.fHash && this->eq(rh);
-    }
-
-protected:
-    virtual bool lt(const GrKey& rh) const = 0;
-    virtual bool eq(const GrKey& rh) const = 0;
-
-private:
-    const Hash fHash;
-
-    typedef SkRefCnt INHERITED;
-};
-
-#endif