Modified text-decoration.html to better test that the values can be in
any order, and that it adopts the color from the `color` property if no
decoration color is specified. Right now, it always does because we do
not support a different decoration color. Later, we need to support the
`currentcolor` special CSS value for this purpose.
This detects and resolves these in the text-decoration property, in any
order:
- text-decoration-color
- text-decoration-line
- text-decoration-style
Only the solid underline renders, but all three sub-properties are
assigned correctly.
