Create a top-level "third_party" directory

This directory now contains third_party software that is vendored into
the Servo source tree. The idea is that it would eventually hold
webrender and other crates from mozilla-central as well with a standard
patch management approach for each.

third_party/WebIDL/tests/test_special_methods.py

@@ -0,0 +1,117 @@
+import WebIDL
+
+
+def WebIDLTest(parser, harness):
+    parser.parse(
+        """
+        interface SpecialMethods {
+          getter long long (unsigned long index);
+          setter long long (unsigned long index, long long value);
+          getter boolean (DOMString name);
+          setter boolean (DOMString name, boolean value);
+          deleter boolean (DOMString name);
+          readonly attribute unsigned long length;
+        };
+
+        interface SpecialMethodsCombination {
+          getter deleter boolean (DOMString name);
+        };
+    """
+    )
+
+    results = parser.finish()
+
+    def checkMethod(
+        method,
+        QName,
+        name,
+        static=False,
+        getter=False,
+        setter=False,
+        deleter=False,
+        legacycaller=False,
+        stringifier=False,
+    ):
+        harness.ok(isinstance(method, WebIDL.IDLMethod), "Should be an IDLMethod")
+        harness.check(method.identifier.QName(), QName, "Method has the right QName")
+        harness.check(method.identifier.name, name, "Method has the right name")
+        harness.check(method.isStatic(), static, "Method has the correct static value")
+        harness.check(method.isGetter(), getter, "Method has the correct getter value")
+        harness.check(method.isSetter(), setter, "Method has the correct setter value")
+        harness.check(
+            method.isDeleter(), deleter, "Method has the correct deleter value"
+        )
+        harness.check(
+            method.isLegacycaller(),
+            legacycaller,
+            "Method has the correct legacycaller value",
+        )
+        harness.check(
+            method.isStringifier(),
+            stringifier,
+            "Method has the correct stringifier value",
+        )
+
+    harness.check(len(results), 2, "Expect 2 interfaces")
+
+    iface = results[0]
+    harness.check(len(iface.members), 6, "Expect 6 members")
+
+    checkMethod(
+        iface.members[0],
+        "::SpecialMethods::__indexedgetter",
+        "__indexedgetter",
+        getter=True,
+    )
+    checkMethod(
+        iface.members[1],
+        "::SpecialMethods::__indexedsetter",
+        "__indexedsetter",
+        setter=True,
+    )
+    checkMethod(
+        iface.members[2],
+        "::SpecialMethods::__namedgetter",
+        "__namedgetter",
+        getter=True,
+    )
+    checkMethod(
+        iface.members[3],
+        "::SpecialMethods::__namedsetter",
+        "__namedsetter",
+        setter=True,
+    )
+    checkMethod(
+        iface.members[4],
+        "::SpecialMethods::__nameddeleter",
+        "__nameddeleter",
+        deleter=True,
+    )
+
+    iface = results[1]
+    harness.check(len(iface.members), 1, "Expect 1 member")
+
+    checkMethod(
+        iface.members[0],
+        "::SpecialMethodsCombination::__namedgetterdeleter",
+        "__namedgetterdeleter",
+        getter=True,
+        deleter=True,
+    )
+
+    parser = parser.reset()
+
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface IndexedDeleter {
+              deleter undefined(unsigned long index);
+            };
+            """
+        )
+        parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "There are no indexed deleters")