Add plumbing for font-stretch

Source/core/css/StylePropertySerializer.cpp

Index: Source/core/css/StylePropertySerializer.cpp
diff --git a/Source/core/css/StylePropertySerializer.cpp b/Source/core/css/StylePropertySerializer.cpp
index d1ab84000b4f953dcf2a7d5a6f44b2f588bd47b8..eb31df7958fb67bb05f3304ed9da1518f3769728 100644
--- a/Source/core/css/StylePropertySerializer.cpp
+++ b/Source/core/css/StylePropertySerializer.cpp
@@ -132,6 +132,7 @@ String StylePropertySerializer::asText() const
         case CSSPropertyFontFamily:
         case CSSPropertyLineHeight:
         case CSSPropertyFontSize:
+        case CSSPropertyFontStretch:
         case CSSPropertyFontStyle:
         case CSSPropertyFontVariant:
         case CSSPropertyFontWeight:
@@ -366,6 +367,7 @@ void StylePropertySerializer::appendFontLonghandValueIfExplicit(CSSPropertyID pr
     case CSSPropertyFontStyle:
         break; // No prefix.
     case CSSPropertyFontFamily:
+    case CSSPropertyFontStretch:
     case CSSPropertyFontVariant:
     case CSSPropertyFontWeight:
         prefix = ' ';
@@ -402,6 +404,7 @@ String StylePropertySerializer::fontValue() const
     appendFontLonghandValueIfExplicit(CSSPropertyFontStyle, result, commonValue);
     appendFontLonghandValueIfExplicit(CSSPropertyFontVariant, result, commonValue);
     appendFontLonghandValueIfExplicit(CSSPropertyFontWeight, result, commonValue);
+    appendFontLonghandValueIfExplicit(CSSPropertyFontStretch, result, commonValue);
     if (!result.isEmpty())
         result.append(' ');
     result.append(fontSizeProperty.value()->cssText());