Make CSSSupportsRule function arguments non-optional

LayoutTests/css3/supports-cssom.html

Index: LayoutTests/css3/supports-cssom.html
diff --git a/LayoutTests/css3/supports-cssom.html b/LayoutTests/css3/supports-cssom.html
index d08638d3461430e3e3b405c32e3de68aae533a9f..f396a580af03b7b20a5bccbcc07d245c89d24435 100644
--- a/LayoutTests/css3/supports-cssom.html
+++ b/LayoutTests/css3/supports-cssom.html
@@ -73,6 +73,11 @@
                           "}\n" +
                           "}");
 
+    debug("\nMissing argument exceptions.");
+    shouldThrow("rules[0].insertRule()");
+    shouldThrow("rules[0].insertRule('@media all {}')");
+    shouldThrow("rules[0].deleteRule()");
+
     debug("\nInserting and deleting rules.");
     evalAndLog("rules[0].insertRule('@media all { #s { width: 0px; } }', 2)");
     shouldEvaluateTo("rules[0].cssRules.length", 3);