RFR(JDK12/JAXP/java.xml) 8206164: forgot to "throw" TransformerConfigurationException

[Joe Wang]

Hi,

Please review a quick fix for a missing throw in what supposed to be a 
throw statement.

JBS: https://bugs.openjdk.java.net/browse/JDK-8206164
webrev: http://cr.openjdk.java.net/~joehw/jdk12/8206164/webrev/

Thanks,
Joe