| OLD | NEW |
| 1 | 1 This is a testharness.js-based test. |
| 2 PASS register a type extension | 2 PASS register a type extension |
| 3 PASS register a type extension with a non-element prototype | 3 PASS register a type extension with a non-element prototype |
| 4 PASS register a type extension of an unknown element | 4 PASS register a type extension of an unknown element |
| 5 PASS register a type extension of an SVG element | 5 PASS register a type extension of an SVG element |
| 6 PASS register a type extension of an element whose interface is HTMLElement | 6 PASS register a type extension of an element whose interface is HTMLElement |
| 7 PASS register a type extensions of an interface with multiple element names | 7 PASS register a type extensions of an interface with multiple element names |
| 8 PASS register a type extension with unusual case | 8 PASS register a type extension with unusual case |
| 9 PASS registering a type extension of a custom tag should fail | 9 PASS registering a type extension of a custom tag should fail |
| 10 Harness: the test ran to completion. |
| 10 | 11 |
| OLD | NEW |