MD Settings: bump iron-list version.

third_party/polymer/v1_0/bower.json

 {
   "name": "chromium",
   "private": true,
   "dependencies": {
     "font-roboto": "PolymerElements/font-roboto#1.0.1",
     "iron-a11y-announcer": "PolymerElements/iron-a11y-announcer#1.0.5",
     "iron-a11y-keys-behavior": "PolymerElements/iron-a11y-keys-behavior#1.1.9",
     "iron-a11y-keys": "PolymerElements/iron-a11y-keys#1.0.7",
     "iron-autogrow-textarea": "PolymerElements/iron-autogrow-textarea#1.0.13",
     "iron-behaviors": "PolymerElements/iron-behaviors#1.0.17",
     "iron-checked-element-behavior": "PolymerElements/iron-checked-element-behavior#1.0.5",
     "iron-collapse": "PolymerElements/iron-collapse#1.2.1",
     "iron-dropdown": "PolymerElements/iron-dropdown#1.5.2",
     "iron-fit-behavior": "PolymerElements/iron-fit-behavior#1.2.5",
     "iron-flex-layout": "PolymerElements/iron-flex-layout#1.3.1",
     "iron-form-element-behavior": "PolymerElements/iron-form-element-behavior#1.0.6",
     "iron-icon": "PolymerElements/iron-icon#1.0.10",
     "iron-iconset-svg": "PolymerElements/iron-iconset-svg#1.0.11",
     "iron-icons": "PolymerElements/iron-icons#1.1.3",
     "iron-input": "PolymerElements/iron-input#1.0.10",
-    "iron-list": "PolymerElements/iron-list#1.3.12",
+    "iron-list": "PolymerElements/iron-list#1.4.4",
     "iron-location": "PolymerElements/iron-location#0.8.8",
     "iron-media-query": "PolymerElements/iron-media-query#1.0.8",
     "iron-menu-behavior": "PolymerElements/iron-menu-behavior#1.1.10",
     "iron-meta": "PolymerElements/iron-meta#1.1.2",
     "iron-overlay-behavior": "PolymerElements/iron-overlay-behavior#1.10.2",
     "iron-pages": "PolymerElements/iron-pages#1.0.8",
     "iron-range-behavior": "PolymerElements/iron-range-behavior#1.0.6",
     "iron-resizable-behavior": "PolymerElements/iron-resizable-behavior#1.0.5",
     "iron-scroll-target-behavior": "PolymerElements/iron-scroll-target-behavior#1.1.0",
     "iron-scroll-threshold": "PolymerElements/iron-scroll-threshold#1.0.2",
@@ skipping 25 matching lines @@
     "paper-spinner": "PolymerElements/paper-spinner#1.2.0",
     "paper-styles": "PolymerElements/paper-styles#1.1.4",
     "paper-tabs": "PolymerElements/paper-tabs#1.6.2",
     "paper-toggle-button": "PolymerElements/paper-toggle-button#1.3.0",
     "paper-toolbar": "PolymerElements/paper-toolbar#1.1.6",
     "paper-tooltip": "PolymerElements/paper-tooltip#1.1.3",
     "polymer": "Polymer/polymer#1.8.1",
     "web-animations-js": "web-animations/web-animations-js#2.2.2"
   }
 }