Expose the CSSSupportsRule interface object

LayoutTests/css3/supports-cssom-expected.txt

Index: LayoutTests/css3/supports-cssom-expected.txt
diff --git a/LayoutTests/css3/supports-cssom-expected.txt b/LayoutTests/css3/supports-cssom-expected.txt
index 3e20cae211cf21affabaaadcf3e1f117e716e139..e51a269ed00a5c6d49a513e1f834c469635a158f 100644
--- a/LayoutTests/css3/supports-cssom-expected.txt
+++ b/LayoutTests/css3/supports-cssom-expected.txt
@@ -6,9 +6,11 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 PASS CSSRule.SUPPORTS_RULE is defined.
 rules = document.styleSheets[1].cssRules
 PASS rules.length is 4
+PASS rules[0] is an instance of CSSSupportsRule
 PASS rules[0].type is CSSRule.SUPPORTS_RULE
 PASS rules[0].cssRules.length is 2
 PASS rules[0].cssRules[0].type is CSSRule.STYLE_RULE
+PASS rules[0].cssRules[1] is an instance of CSSSupportsRule
 PASS rules[0].cssRules[1].type is CSSRule.SUPPORTS_RULE
 PASS rules[0].cssRules[1].cssRules.length is 1
 PASS rules[0].cssRules[1].cssRules[0].type is CSSRule.STYLE_RULE
@@ -23,6 +25,7 @@ rules[0].deleteRule(2)
 PASS rules[0].cssRules.length is 2
 rules[0].cssRules[1].insertRule('@supports (display: rainbow) {}', 1)
 PASS rules[0].cssRules[1].cssRules.length is 2
+PASS rules[0].cssRules[1].cssRules[1] is an instance of CSSSupportsRule
 PASS rules[0].cssRules[1].cssRules[1].type is CSSRule.SUPPORTS_RULE
 rules[0].cssRules[1].deleteRule(1)
 PASS rules[0].cssRules.length is 2
@@ -38,6 +41,7 @@ PASS rules[1].conditionText is "((  (     padding: 0)    and (display: none)) or
 @supports rule nested inside a media rule.
 PASS rules[2].type is CSSRule.MEDIA_RULE
 PASS rules[2].cssRules.length is 1
+PASS rules[2].cssRules[0] is an instance of CSSSupportsRule
 PASS rules[2].cssRules[0].type is CSSRule.SUPPORTS_RULE
 PASS rules[2].cssRules[0].conditionText is "( padding: 0)"
 PASS rules[0].cssRules[1].cssRules.length is 1