impl part of SKFontMgr for mac

include/ports/SkFontMgr.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkFontMgr_DEFINED
 #define SkFontMgr_DEFINED
 
 #include "SkRefCnt.h"
 #include "SkFontStyle.h"
 
 class SkData;
 class SkStream;
 class SkString;
 
 class SkFontStyleSet : public SkRefCnt {
 public:
-    int count() const;
-    void getStyle(int index, SkFontStyle*) const;
-    SkTypeface* createTypeface(int index) const;
+    virtual int count() = 0;
+    virtual void getStyle(int index, SkFontStyle*, SkString* style) = 0;
+    virtual SkTypeface* createTypeface(int index) = 0;
 };
 
 class SkFontMgr : public SkRefCnt {
 public:
     int countFamilies();
     void getFamilyName(int index, SkString* familyName);
     SkFontStyleSet* createStyleSet(int index);
 
     /**
      *  Find the closest matching typeface to the specified familyName and style
@@ skipping 48 matching lines @@
     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) = 0;
 
 private:
     static SkFontMgr* Factory();    // implemented by porting layer
     static SkMutex* Mutex();        // implemented by porting layer
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif