Add plumbing for font-stretch

LayoutTests/fast/css/font-shorthand-expected.txt

Index: LayoutTests/fast/css/font-shorthand-expected.txt
diff --git a/LayoutTests/fast/css/font-shorthand-expected.txt b/LayoutTests/fast/css/font-shorthand-expected.txt
index 3c3391bbe3e527b1fe757b084b293d7e5e5a0cb5..4db06b75fcd19283f97acce56c1491641e84c10e 100644
--- a/LayoutTests/fast/css/font-shorthand-expected.txt
+++ b/LayoutTests/fast/css/font-shorthand-expected.txt
@@ -3,6 +3,7 @@ Font for '12px monospace':
 font-style: normal
 font-variant: normal
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: normal
 font-family: monospace
@@ -11,6 +12,7 @@ Font for '12px/24px serif':
 font-style: normal
 font-variant: normal
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: 24px
 font-family: serif
@@ -19,6 +21,7 @@ Font for 'normal 12px serif':
 font-style: normal
 font-variant: normal
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: normal
 font-family: serif
@@ -27,6 +30,7 @@ Font for 'normal normal 12px serif':
 font-style: normal
 font-variant: normal
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: normal
 font-family: serif
@@ -35,6 +39,7 @@ Font for 'normal normal normal 12px serif':
 font-style: normal
 font-variant: normal
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: normal
 font-family: serif
@@ -43,6 +48,7 @@ Font for 'italic small-caps 12px/24px serif':
 font-style: italic
 font-variant: small-caps
 font-weight: normal
+font-stretch: normal
 font-size: 12px
 line-height: 24px
 font-family: serif
@@ -51,6 +57,7 @@ Font for 'italic bold 12px/24px serif':
 font-style: italic
 font-weight: bold
 font-variant: normal
+font-stretch: normal
 font-size: 12px
 line-height: 24px
 font-family: serif
@@ -59,6 +66,7 @@ Font for 'small-caps bold 14px/28px Arial, sans-serif':
 font-variant: small-caps
 font-weight: bold
 font-style: normal
+font-stretch: normal
 font-size: 14px
 line-height: 28px
 font-family: Arial, sans-serif
@@ -67,6 +75,7 @@ Font for 'italic small-caps bold 14px/28px Arial, sans-serif':
 font-style: italic
 font-variant: small-caps
 font-weight: bold
+font-stretch: normal
 font-size: 14px
 line-height: 28px
 font-family: Arial, sans-serif