Give error-toast a duration argument

res/imp/error-toast-sk.html

 <!-- The <error-toast-sk> custom element declaration.
 
   Listens for 'error-sk' events that bubble up to the document
   and displays them.
 
   The 'error-sk' event should have 'detail' of the form:
 
     {
       message: "The error message to display goes here.",
+      duration: Integer, the number of ms to display or 0 for indefinitely.
+                Defaults to 10000 (10s)
     }
 
   Attributes:
   Events:
   Methods:
 -->
 <link rel="import" href="/res/imp/bower_components/paper-toast/paper-toast.html" />
 
 <dom-module id="error-toast-sk">
   <template>
-    <paper-toast id=toast duration=10000></paper-toast>
+    <paper-toast id=toast></paper-toast>
   </template>
 </dom-module>
 
 <script>
   Polymer({
     is: "error-toast-sk",
     ready: function() {
       document.addEventListener('error-sk', function(e) {
+        this.$.toast.close();
         if (e.detail.message) {
           this.$.toast.text = e.detail.message;
+          // duration = 0 is a valid input for "keep open indefinitely".
+          this.$.toast.duration = (e.detail.duration === undefined ? 10000 : e.detail.duration)
           this.$.toast.show();
         } else {
           console.log("Empty message?", e);
         }
       }.bind(this));
     },
   });
 </script>