CREDENTIAL: Do type checks for credential constructors.

third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html

Index: third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html b/third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html
index 9183351fde4ff633affba5838f1a83e979e5c57b..3a02a114ae8a0ed39fef7ebf8a5c0f0f3f0e3334 100644
--- a/third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html
+++ b/third_party/WebKit/LayoutTests/http/tests/credentialmanager/federatedcredential-basics.html
@@ -91,4 +91,25 @@ test(function() {
         });
     });
 }, 'Construct a FederatedCredential with an invalid federation URL.');
+
+test(function() {
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential(); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({}); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'id': undefined }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'id': '' }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'provider': undefined }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'provider': '' }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'id': undefined, 'provider': undefined }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'id': undefined, 'provider': '' }); });
+    assert_throws(new TypeError(),
+                  () => { new FederatedCredential({ 'id': undefined, 'provider': undefined }); });
+}, 'FederatedCredential objects require IDs and Providers');
 </script>