IDL: Support union type arrays and sequences for method arguments

Source/core/testing/UnionTypesTest.idl

Index: Source/core/testing/UnionTypesTest.idl
diff --git a/Source/core/testing/UnionTypesTest.idl b/Source/core/testing/UnionTypesTest.idl
index efc8a1801ea0667c577082a3a8669366c03c1be1..f3375202d1deacda8504db60588e0dc4c965f608 100644
--- a/Source/core/testing/UnionTypesTest.idl
+++ b/Source/core/testing/UnionTypesTest.idl
@@ -12,4 +12,6 @@
     [ImplementedAs=doubleOrStringArg] DOMString doubleOrStringDefaultDoubleArg(optional (double or DOMString) arg = 3.14);
     [ImplementedAs=doubleOrStringArg] DOMString doubleOrStringDefaultStringArg(optional (double or DOMString) arg = "foo");
     [ImplementedAs=doubleOrStringArg] DOMString doubleOrStringDefaultNullArg(optional (double or DOMString)? arg = null);
+    DOMString doubleOrStringArrayArg((double or DOMString)[] arg);
+    DOMString doubleOrStringSequenceArg(sequence<(double or DOMString)> arg);
 };