Expose API for gx font variation axes.

src/ports/SkFontHost_FreeType_common.h

 /*
  * Copyright 2006-2012 The Android Open Source Project
  * Copyright 2012 Mozilla Foundation
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SKFONTHOST_FREETYPE_COMMON_H_
 #define SKFONTHOST_FREETYPE_COMMON_H_
 
 #include "SkGlyph.h"
 #include "SkMutex.h"
 #include "SkScalerContext.h"
 #include "SkTypeface.h"
 #include "SkTypes.h"
 
+#include "SkFontMgr.h"
+
 #include <ft2build.h>
 #include FT_FREETYPE_H
 
 class SkScalerContext_FreeType_Base : public SkScalerContext {
 protected:
     // See http://freetype.sourceforge.net/freetype2/docs/reference/ft2-bitmap_handling.html#FT_Bitmap_Embolden
     // This value was chosen by eyeballing the result in Firefox and trying to match it.
     static const FT_Pos kBitmapEmboldenStrength = 1 << 6;
 
     SkScalerContext_FreeType_Base(SkTypeface* typeface, const SkDescriptor *desc)
@@ skipping 20 matching lines @@
             SkFourByteTag fTag;
             SkFixed fMinimum;
             SkFixed fDefault;
             SkFixed fMaximum;
         };
         using AxisDefinitions = SkSTArray<4, AxisDefinition, true>;
         bool recognizedFont(SkStream* stream, int* numFonts) const;
         bool scanFont(SkStream* stream, int ttcIndex,
                       SkString* name, SkFontStyle* style, bool* isFixedPitch,
                       AxisDefinitions* axes) const;
+        static void computeAxisValues(
+            AxisDefinitions axisDefinitions,
+            const SkFontMgr::FontParameters::Axis* requestedAxis, int requestedAxisCount,
+            SkFixed* axisValues,
+            const SkString& name);
+
     private:
         FT_Face openFace(SkStream* stream, int ttcIndex, FT_Stream ftStream) const;
         FT_Library fLibrary;
         mutable SkMutex fLibraryMutex;
     };
 
 protected:
     SkTypeface_FreeType(const SkFontStyle& style, SkFontID uniqueID, bool isFixedPitch)
         : INHERITED(style, uniqueID, isFixedPitch)
         , fGlyphCount(-1)
@@ skipping 17 matching lines @@
     virtual size_t onGetTableData(SkFontTableTag, size_t offset,
                                   size_t length, void* data) const override;
 
 private:
     mutable int fGlyphCount;
 
     typedef SkTypeface INHERITED;
 };
 
 #endif // SKFONTHOST_FREETYPE_COMMON_H_