fix test for font_size

Author: sonwow

test.rs

@@ -334,22 +334,21 @@ fn test_font_family_specific() {
 }
 
 #[test]
-#[ignore]
 fn test_font_size() {
-    let style = "div { font-size: 10pt; }";
-    do single_div_test(style) |computed| {
+    let style = "span { font-size: 10pt; }";
+    do child_test(style) |computed| {
         assert!(computed.font_size() == Specified(CSSFontSizeLength(Pt(10.0))));
     }
-    let style = "div { font-size: 10%; }";
-    do single_div_test(style) |computed| {
+    let style = "span { font-size: 10%; }";
+    do child_test(style) |computed| {
         assert!(computed.font_size() == Specified(CSSFontSizePercentage(10.0)));
     }
-    let style = "div { font-size: small; }";
-    do single_div_test(style) |computed| {
+    let style = "span { font-size: small; }";
+    do child_test(style) |computed| {
         assert!(computed.font_size() == Specified(CSSFontSizeAbsoluteSize(Small)));
     }
-    let style = "div { font-size: smaller; }";
-    do single_div_test(style) |computed| {
+    let style = "span { font-size: smaller; }";
+    do child_test(style) |computed| {
         assert!(computed.font_size() == Specified(CSSFontSizeRelativeSize(Smaller)));
     }
 }