Tests that invalid rule inside @-rule doesn't break source code matching (http://crbug.com/317499).
[expanded]
element.style { ()
[expanded]
#main { (styles-sour…per.html:25 -> styles-source-lines-recovery-helper.html:25:8)
color: white;
[expanded]
#main { (styles-sour…per.html:16 -> styles-source-lines-recovery-helper.html:16:8)
/-- overloaded --/ color: blue;
[expanded]
#main { (styles-sour…lper.html:7 -> styles-source-lines-recovery-helper.html:7:8)
/-- overloaded --/ color: red;
[expanded]
div { (user agent stylesheet)
display: block;
unicode-bidi: isolate;