Expand system font values during property parsing.

Source/core/css/CSSProperties.in

Index: Source/core/css/CSSProperties.in
diff --git a/Source/core/css/CSSProperties.in b/Source/core/css/CSSProperties.in
index 7dcdfcf0ca7eb2dcb36eb3e1397272a961d31d33..41522792a361c6ab056fd8254a93fed9d5481223 100644
--- a/Source/core/css/CSSProperties.in
+++ b/Source/core/css/CSSProperties.in
@@ -82,9 +82,6 @@
 // Other properties can depend upon high priority properties (e.g. font-size / ems)
 color animatable, inherited, custom_all
 direction inherited, custom_value
-// FIXME: This is a mess due to crbug.com/353932. Shorthands shouldn't have
-// any StyleBuilder handling!
-font custom_all, longhands=font-family;font-size;font-style;font-variant;font-weight;font-stretch;line-height
 font-family inherited, font, type_name=FontDescription::FamilyDescription, name_for_methods=FamilyDescription, converter=convertFontFamily
 font-kerning inherited, font, type_name=FontDescription::Kerning, name_for_methods=Kerning
 font-size animatable, inherited, font, name_for_methods=Size, converter=convertFontSize
@@ -462,6 +459,7 @@ border-top longhands=border-top-width;border-top-style;border-top-color
 border-width longhands=border-top-width;border-right-width;border-bottom-width;border-left-width
 flex longhands=flex-grow;flex-shrink;flex-basis
 flex-flow longhands=flex-direction;flex-wrap
+font longhands=font-family;font-size;font-style;font-variant;font-weight;font-stretch;line-height
 grid runtime_flag=CSSGridLayout, longhands=grid-template-columns;grid-template-rows;grid-template-areas;grid-auto-flow;grid-auto-columns;grid-auto-rows
 grid-area runtime_flag=CSSGridLayout, longhands=grid-row-start;grid-column-start;grid-row-end;grid-column-end
 grid-column runtime_flag=CSSGridLayout, longhands=grid-column-start;grid-column-end