Do not treat '0' as 'none' for font-size-adjust

Source/core/css/resolver/FontBuilder.h

Index: Source/core/css/resolver/FontBuilder.h
diff --git a/Source/core/css/resolver/FontBuilder.h b/Source/core/css/resolver/FontBuilder.h
index 78242334f5650779961f7a91486e697fe3e0abc1..cf91993a54a107f528811ff44d36932615be56b7 100644
--- a/Source/core/css/resolver/FontBuilder.h
+++ b/Source/core/css/resolver/FontBuilder.h
@@ -76,7 +76,7 @@ public:
     static FontFeatureSettings* initialFeatureSettings() { return nullptr; }
     static FontDescription::GenericFamilyType initialGenericFamily() { return FontDescription::StandardFamily; }
     static FontDescription::Size initialSize() { return FontDescription::Size(FontSize::initialKeywordSize(), 0.0f, false); }
-    static float initialSizeAdjust() { return 0; }
+    static float initialSizeAdjust() { return FontSizeAdjustNone; }
     static TextRenderingMode initialTextRendering() { return AutoTextRendering; }
     static FontVariant initialVariant() { return FontVariantNormal; }
     static FontDescription::VariantLigatures initialVariantLigatures() { return FontDescription::VariantLigatures(); }