Apply behaviour change fix from upstream for previous XPath change.

BUG=58731
TEST=NONE

Review URL: http://codereview.chromium.org/4027006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@63572 0039d316-1c4b-4281-b951-d872f2087c98
xmlXPathCastStringToBoolean (const xmlChar *val) {
    if ((val == NULL) || (xmlStrlen(val) == 0))
	return(0);
    return(1);
}

xmlXPathCastStringToBoolean (const xmlChar *val) {
    if ((val == NULL) || (xmlStrlen(val) == 0))
	return(0);
    return(1);
}
