Roll third_party/polymer.

third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js

Index: third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js
diff --git a/third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js b/third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js
index 291e7de4c4758e36029e74eda4d0d0c39eabbc7e..2dcc7b2e6950811a90c83ab279d4ff8d4f8dcd30 100644
--- a/third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js
+++ b/third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js
@@ -32,8 +32,14 @@
     properties: {
 
       /**
-       * If you want to use the attribute value of an element for `selected` instead of the index,
-       * set this to the name of the attribute.
+       * If you want to use an attribute value or property of an element for
+       * `selected` instead of the index, set this to the name of the attribute
+       * or property. Hyphenated values are converted to camel case when used to
+       * look up the property of a selectable element. Camel cased values are
+       * *not* converted to hyphenated values for attribute lookup. It's
+       * recommended that you provide the hyphenated form of the name so that
+       * selection works in both cases. (Use `attr-or-property-name` instead of
+       * `attrOrPropertyName`.)
        */
       attrForSelected: {
         type: String,
@@ -94,6 +100,15 @@
       },
 
       /**
+       * Default fallback if the selection based on selected with `attrForSelected`
+       * is not found.
+       */
+      fallbackSelection: {
+        type: String,
+        value: null
+      },
+
+      /**
        * The list of items from which a selection can be made.
        */
       items: {
@@ -123,7 +138,8 @@
 
     observers: [
       '_updateAttrForSelected(attrForSelected)',
-      '_updateSelected(selected)'
+      '_updateSelected(selected)',
+      '_checkFallback(fallbackSelection)'
     ],
 
     created: function() {
@@ -209,6 +225,12 @@
       return this.selected != null;
     },
 
+    _checkFallback: function() {
+      if (this._shouldUpdateSelection) {
+        this._updateSelected();
+      }
+    },
+
     _addListener: function(eventName) {
       this.listen(this, eventName, '_activateHandler');
     },
@@ -230,7 +252,7 @@
 
     _updateAttrForSelected: function() {
       if (this._shouldUpdateSelection) {
-        this.selected = this._indexToValue(this.indexOf(this.selectedItem));        
+        this.selected = this._indexToValue(this.indexOf(this.selectedItem));
       }
     },
 
@@ -240,6 +262,11 @@
 
     _selectSelected: function(selected) {
       this._selection.select(this._valueToItem(this.selected));
+      // Check for items, since this array is populated only when attached
+      // Since Number(0) is falsy, explicitly check for undefined
+      if (this.fallbackSelection && this.items.length && (this._selection.get() === undefined)) {
+        this.selected = this.fallbackSelection;
+      }
     },
 
     _filterItem: function(node) {
@@ -274,7 +301,7 @@
     },
 
     _valueForItem: function(item) {
-      var propValue = item[this.attrForSelected];
+      var propValue = item[Polymer.CaseMap.dashToCamelCase(this.attrForSelected)];
       return propValue != undefined ? propValue : item.getAttribute(this.attrForSelected);
     },