Add crashtest.

layout/xul/base/src/crashtests/366112-1.xul

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+
+<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
+
+<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <nativescrollbar />
+
+</window>

layout/xul/base/src/crashtests/crashtests.list

@@ -3,4 +3,5 @@ load 327776-1.html
 load 329407-1.xml
 load 346083-1.html
 load 346281-1.html
+load 366112-1.xul
 load 377592-1.svg