[MD settings] updating polymer to 1.1.13

third_party/polymer/v1_0/components-chromium/iron-overlay-behavior/iron-overlay-manager-extracted.js

 Polymer.IronOverlayManager = (function() {
 
     var overlays = [];
     var DEFAULT_Z = 10;
     var backdrops = [];
 
     // track overlays for z-index and focus managemant
     function addOverlay(overlay) {
       var z0 = currentOverlayZ();
       overlays.push(overlay);
@@ skipping 13 matching lines @@
 
     function applyOverlayZ(overlay, aboveZ) {
       setZ(overlay, aboveZ + 2);
     }
 
     function setZ(element, z) {
       element.style.zIndex = z;
     }
 
     function currentOverlay() {
-      return overlays[overlays.length-1];
+      var i = overlays.length - 1;
+      while (overlays[i] && !overlays[i].opened) {
+        --i;
+      }
+      return overlays[i];
     }
 
     function currentOverlayZ() {
       var z;
       var current = currentOverlay();
       if (current) {
         var z1 = window.getComputedStyle(current).zIndex;
         if (!isNaN(z1)) {
           z = Number(z1);
         }
@@ skipping 37 matching lines @@
       addOverlay: addOverlay,
       removeOverlay: removeOverlay,
       currentOverlay: currentOverlay,
       currentOverlayZ: currentOverlayZ,
       focusOverlay: focusOverlay,
       trackBackdrop: trackBackdrop,
       getBackdrops: getBackdrops
     };
 
   })();