[letter-spacing-valid.html]
[e.style['letter-spacing'\] = "120%" should set the property value]
expected: FAIL
[e.style['letter-spacing'\] = "-10%" should set the property value]
expected: FAIL
[e.style['letter-spacing'\] = "calc(2ch - 30%)" should set the property value]
expected: FAIL
[e.style['letter-spacing'\] = "calc(40% + 50px)" should set the property value]
expected: FAIL