CREDENTIAL: Add 'PasswordCredential::toFormData()'

LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html

Index: LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html
diff --git a/LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html b/LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html
index 6b928ea49287c10d6b7713dc2555cebd58dd6bde..2085321baed8b4e9b0bd7c92ae54dd8e39e5ce06 100644
--- a/LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html
+++ b/LayoutTests/http/tests/credentialmanager/passwordcredential-basics.html
@@ -8,20 +8,18 @@ test(function() {
     var credential = new PasswordCredential('id', 'pencil', 'name', 'https://example.com/icon.png');
 
     verify_interface('PasswordCredential', credential, {
-        formData: 'object',
         id: 'string',
         name: 'string',
         iconURL: 'string',
-        password: 'string',
         type: 'string'
     });
 
-    assert_true(credential.formData instanceof FormData);
     assert_equals(credential.id, 'id');
     assert_equals(credential.name, 'name');
     assert_equals(credential.iconURL, 'https://example.com/icon.png');
-    assert_equals(credential.password, 'pencil');
     assert_equals(credential.type, 'password');
+
+    assert_true(credential.toFormData() instanceof FormData);
 }, 'Interfaces and attributes of PasswordCredential');
 
 test(function() {
@@ -36,8 +34,8 @@ test(function() {
     assert_equals(credential.id, 'id');
     assert_equals(credential.name, 'name');
     assert_equals(credential.iconURL, '');
-    assert_equals(credential.password, 'pencil');
     assert_equals(credential.type, 'password');
+    assert_true(credential.toFormData() instanceof FormData);
 
 }, 'Construct a PasswordCredential with an empty icon URL.');
 
@@ -47,8 +45,35 @@ test(function() {
     assert_equals(credential.id, 'id');
     assert_equals(credential.name, '');
     assert_equals(credential.iconURL, '');
-    assert_equals(credential.password, 'pencil');
     assert_equals(credential.type, 'password');
-
+    assert_true(credential.toFormData() instanceof FormData);
 }, 'Construct a PasswordCredential with an empty name and icon URL.');
+
+test(function() {
+    var credential = new PasswordCredential('id', 'pencil');
+
+    var fd = credential.toFormData();
+    fd.append('n1', 'v1');
+    fd.append('n2', 'v2');
+    fd.append('n3', 'v3');
+    fd.append('n1', 'v4');
+    fd.append('n2', 'v5');
+    fd.append('n3', 'v6');
+
+    assert_equals(fd.get('n1'), null);
+    assert_equals(fd.get('n2'), null);
+    assert_equals(fd.get('n3'), null);
+
+    assert_equals(fd.has('n1'), false);
+    assert_equals(fd.has('n2'), false);
+    assert_equals(fd.has('n3'), false);
+
+    assert_array_equals(fd.getAll('n1'), []);
+    assert_array_equals(fd.getAll('n2'), []);
+    assert_array_equals(fd.getAll('n3'), []);
+
+    for(var entry of fd) {
+        assert_unreached("There should be nothing to iterate here.");
+    }
+}, 'Verify properties of opaque FormData.');
 </script>