Call hb_font_set_variation if font variations are provided.

Test: None
Change-Id: I203d9ba7e1a1fcfdb10cd6a711d9a35136cbddd6

engine/src/flutter/include/minikin/MinikinFont.h

@@ -126,6 +126,8 @@ public:
         return 0;
     }
 
+    virtual const std::vector<minikin::FontVariation>& GetAxes() const = 0;
+
     virtual MinikinFont* createFontWithVariation(const std::vector<FontVariation>&) const {
         return nullptr;
     }

engine/src/flutter/include/minikin/MinikinFontFreeType.h

@@ -50,6 +50,10 @@ public:
 
     const void* GetTable(uint32_t tag, size_t* size, MinikinDestroyFunc* destroy);
 
+    const std::vector<minikin::FontVariation>& GetAxes() const {
+        return mAxes;
+    }
+
     // TODO: provide access to raw data, as an optimization.
 
     // Not a virtual method, as the protocol to access rendered
@@ -63,6 +67,7 @@ public:
 private:
     FT_Face mTypeface;
     static int32_t sIdCounter;
+    std::vector<minikin::FontVariation> mAxes;
 };
 
 }  // namespace minikin

engine/src/flutter/libs/minikin/HbFontCache.cpp

@@ -117,6 +117,11 @@ hb_font_t* getHbFontLocked(MinikinFont* minikinFont) {
     hb_font_set_scale(parent_font, upem, upem);
 
     font = hb_font_create_sub_font(parent_font);
+    std::vector<hb_variation_t> variations;
+    for (const FontVariation& variation : minikinFont->GetAxes()) {
+        variations.push_back({variation.axisTag, variation.value});
+    }
+    hb_font_set_variations(font, variations.data(), variations.size());
     hb_font_destroy(parent_font);
     hb_face_destroy(face);
     fontCache->put(fontId, font);

engine/src/flutter/sample/MinikinSkia.h

@@ -26,12 +26,15 @@ public:
         const MinikinPaint& paint) const;
 
     const void* GetTable(uint32_t tag, size_t* size, MinikinDestroyFunc* destroy);
+    const std::vector<minikin::FontVariation>& GetAxes() const {
+        return mAxes;
+    }
 
     SkTypeface *GetSkTypeface();
 
 private:
     sk_sp<SkTypeface> mTypeface;
-
+    std::vector<minikin::FontVariation> mAxes;
 };
 
 }  // namespace minikin

engine/src/flutter/tests/util/MinikinFontForTest.h

@@ -38,11 +38,11 @@ public:
             const MinikinPaint& paint) const;
 
     const std::string& fontPath() const { return mFontPath; }
-    const std::vector<FontVariation>& variations() const { return mVariations; }
 
     const void* GetFontData() const { return mFontData; }
     size_t GetFontSize() const { return mFontSize; }
     int GetFontIndex() const { return mFontIndex; }
+    const std::vector<minikin::FontVariation>& GetAxes() const { return mVariations; }
     MinikinFont* createFontWithVariation(const std::vector<FontVariation>& variations) const;
 private:
     MinikinFontForTest() = delete;