Add Unicode Variation Selector support to harfBuzzGetGlyph

Source/platform/fonts/shaping/HarfBuzzShaper.h

Index: Source/platform/fonts/shaping/HarfBuzzShaper.h
diff --git a/Source/platform/fonts/shaping/HarfBuzzShaper.h b/Source/platform/fonts/shaping/HarfBuzzShaper.h
index 5fe820b69aa49d82fb2d0463876e156fcbcd00cb..4f12c76ddf3774c9f996273ceaaa96237c5a6810 100644
--- a/Source/platform/fonts/shaping/HarfBuzzShaper.h
+++ b/Source/platform/fonts/shaping/HarfBuzzShaper.h
@@ -78,6 +78,16 @@ public:
         return false;
     }
 
+    uint16_t glyphForTesting(unsigned runIndex, size_t glyphIndex)
+    {
+        return m_harfBuzzRuns[runIndex]->glyphData(glyphIndex).glyph;
+    }
+
+    float advanceForTesting(unsigned runIndex, size_t glyphIndex)
+    {
+        return m_harfBuzzRuns[runIndex]->glyphData(glyphIndex).advance;
+    }
+
 private:
     struct HarfBuzzRunGlyphData {
         uint16_t glyph;