Roll Polymer from 1.5.0 -> 1.6.0 to pick up native CSS custom props

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

Index: third_party/polymer/v1_0/components-chromium/iron-menu-behavior/iron-menu-behavior-extracted.js
diff --git a/third_party/polymer/v1_0/components-chromium/iron-menu-behavior/iron-menu-behavior-extracted.js b/third_party/polymer/v1_0/components-chromium/iron-menu-behavior/iron-menu-behavior-extracted.js
index b3404038e940c5b524d78a40ae0a0c741476f212..5a2f4206f3f6b1f86b733074788eb98120a4de78 100644
--- a/third_party/polymer/v1_0/components-chromium/iron-menu-behavior/iron-menu-behavior-extracted.js
+++ b/third_party/polymer/v1_0/components-chromium/iron-menu-behavior/iron-menu-behavior-extracted.js
@@ -123,11 +123,12 @@
     /**
      * Focuses the previous item (relative to the currently focused item) in the
      * menu, disabled items will be skipped.
+     * Loop until length + 1 to handle case of single item in menu.
      */
     _focusPrevious: function() {
       var length = this.items.length;
       var curFocusIndex = Number(this.indexOf(this.focusedItem));
-      for (var i = 1; i < length; i++) {
+      for (var i = 1; i < length + 1; i++) {
         var item = this.items[(curFocusIndex - i + length) % length];
         if (!item.hasAttribute('disabled')) {
           this._setFocusedItem(item);
@@ -139,11 +140,12 @@
     /**
      * Focuses the next item (relative to the currently focused item) in the
      * menu, disabled items will be skipped.
+     * Loop until length + 1 to handle case of single item in menu.
      */
     _focusNext: function() {
       var length = this.items.length;
       var curFocusIndex = Number(this.indexOf(this.focusedItem));
-      for (var i = 1; i < length; i++) {
+      for (var i = 1; i < length + 1; i++) {
         var item = this.items[(curFocusIndex + i) % length];
         if (!item.hasAttribute('disabled')) {
           this._setFocusedItem(item);