import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

testing/web-platform/tests/conformance-checkers/html-aria/name-computation-input/754.html

@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset=utf-8>
+<title>An INPUT type=text, password, checkbox, radio, file, or image, with id="test", with no aria-labelledby and no aria-label, but is referenced by a LABEL element that has an associated CSS :before content rule.</title>
+<style>
+
+label:before
+{
+content:"fancy ";
+}
+</style>
+</head>
+<body>
+<label for="test">fruit</label>
+<input type="checkbox" id="test"/>
+</body>
+</html>
+