Bug 392188 - Don't allow click-through on <browser>s by default. r=Enn

toolkit/content/widgets/browser.xml

@@ -51,6 +51,9 @@
           xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
   <binding id="browser" extends="xul:browser">
+    <content clickthrough="never">
+      <children/>
+    </content>
     <implementation type="application/javascript" implements="nsIAccessibleProvider, nsIObserver, nsIDOMEventListener">
       <property name="accessibleType" readonly="true">
         <getter>