IDL: Treat undefined as missing for optional arguments with defaults

LayoutTests/fast/workers/resources/shared-worker-name.js

 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 }
 
 description("Checks the various use cases around the SharedWorker constructor's optional name parameter");
 
 var currentTest = 0;
 nextTest();
 
@@ skipping 42 matching lines @@
     var worker = new SharedWorker('resources/shared-worker-common.js', '');
     worker.port.postMessage("eval self.foo");
     worker.port.onmessage = function(event) {
         shouldBeEqual("creating worker with empty name", event.data, "self.foo: 1234");
         nextTest();
     };
 }
 
 function test4()
 {
+    // Creating a worker with an undefined name should match an existing worker with no name.
+    var worker = new SharedWorker('resources/shared-worker-common.js', undefined);
+    worker.port.postMessage("eval self.foo");
+    worker.port.onmessage = function(event) {
+        shouldBeEqual("creating worker with an undefined name", event.data, "self.foo: 1234");
+        nextTest();
+    }
+}
+
+function test5()
+{
     // Creating a worker with a different name should not be the same as a worker with no name.
     var worker = new SharedWorker('resources/shared-worker-common.js', 'name');
     worker.port.postMessage("eval self.foo");
     worker.port.onmessage = function(event) {
         shouldBeEqual("creating worker with different name but same URL", event.data, "self.foo: undefined");
         nextTest();
     };
 }
 
-function test5()
+function test6()
 {
     // Creating a worker for an alternate URL with no name should work.
     var worker = new SharedWorker('resources/shared-worker-common.js?url=1');
     worker.port.postMessage("eval self.foo");
     worker.port.onmessage = function(event) {
         shouldBeEqual("creating no-name worker with alternate URL", event.data, "self.foo: undefined");
         nextTest();
     };
 }
 
-function test6()
+function test7()
 {
     // Creating a worker for an alternate URL with empty name should work.
     var worker = new SharedWorker('resources/shared-worker-common.js?url=2', '');
     worker.port.postMessage("eval self.foo");
     worker.port.onmessage = function(event) {
         shouldBeEqual("creating empty name worker with alternate URL", event.data, "self.foo: undefined");
         nextTest();
     };
 }
 
-function test7()
+function test8()
 {
     // Make sure we can create a shared worker with name 'null'.
     try {
         var worker = new SharedWorker('resources/shared-worker-common.js', 'null');
         testPassed("created SharedWorker with name 'null'");
         worker.port.postMessage("eval self.foo = 5678");
         worker.port.onmessage = function(event) {
             shouldBeEqual("setting self.foo", event.data, "self.foo = 5678: 5678");
             nextTest();
         };
     } catch (e) {
         testFailed("SharedWorker with name 'null' threw an exception: " + e);
         done();
     }
 }
 
-function test8()
+function test9()
 {
     // Creating a worker with a null name should match an existing worker with name 'null'
     var worker = new SharedWorker('resources/shared-worker-common.js', null);
     worker.port.postMessage("eval self.foo");
     worker.port.onmessage = function(event) {
         shouldBeEqual("creating worker with a null name", event.data, "self.foo: 5678");
         nextTest();
     }
 }
 
-function test9()
-{
-    // Make sure we can create a shared worker with name 'undefined'.
-    try {
-        var worker = new SharedWorker('resources/shared-worker-common.js', 'undefined');
-        testPassed("created SharedWorker with name 'undefined'");
-        worker.port.postMessage("eval self.foo = 1111");
-        worker.port.onmessage = function(event) {
-            shouldBeEqual("setting self.foo", event.data, "self.foo = 1111: 1111");
-            nextTest();
-        };
-    } catch (e) {
-        testFailed("SharedWorker with name 'undefined' threw an exception: " + e);
-        done();
-    }
-}
-
 function test10()
 {
-    // Creating a worker with an undefined name should match an existing worker with name 'undefined'
-    var worker = new SharedWorker('resources/shared-worker-common.js', undefined);
-    worker.port.postMessage("eval self.foo");
-    worker.port.onmessage = function(event) {
-        shouldBeEqual("creating worker with an undefined name", event.data, "self.foo: 1111");
-        nextTest();
-    }
-}
-
-function test11()
-{
     // Creating a worker with a specific name, the name attribute should be set to worker correctly.
     var worker = new SharedWorker('resources/shared-worker-common.js', "testingNameAttribute");
     worker.port.postMessage("testingNameAttribute");
     worker.port.onmessage = function(event) {
         shouldBeEqual("the name attribute of worker can be set correctly", event.data, "testingNameAttribute");
         nextTest();
     }
 }
 
 function shouldBeEqual(description, a, b)
 {
     if (a == b)
         testPassed(description);
     else
         testFailed(description + " - passed value: " + a + ", expected value: " + b);
 }