Roll Polymer to 1.3.1

third_party/polymer/v1_0/components-chromium/iron-overlay-behavior/bower.json

 {
   "name": "iron-overlay-behavior",
-  "version": "1.3.0",
+  "version": "1.4.1", 
   "license": "http://polymer.github.io/LICENSE.txt",
   "description": "Provides a behavior for making an element an overlay",
   "private": true,
   "main": "iron-overlay-behavior.html",
   "keywords": [
     "web-components",
     "polymer",
     "behavior",
     "overlay"
   ],
   "authors": [
     "The Polymer Authors"
   ],
   "repository": {
     "type": "git",
     "url": "git://github.com/PolymerElements/iron-overlay-behavior.git"
   },
   "dependencies": {
+    "iron-a11y-keys-behavior": "PolymerElements/iron-a11y-keys-behavior#^1.0.0",
     "iron-fit-behavior": "PolymerElements/iron-fit-behavior#^1.0.0",
     "iron-resizable-behavior": "PolymerElements/iron-resizable-behavior#^1.0.0",
     "polymer": "Polymer/polymer#^1.0.0"
   },
   "devDependencies": {
     "iron-component-page": "PolymerElements/iron-component-page#^1.0.0",
+    "iron-demo-helpers": "PolymerElements/iron-demo-helpers#^1.0.0",
     "iron-flex-layout": "PolymerElements/iron-flex-layout#^1.0.0",
     "iron-test-helpers": "PolymerElements/iron-test-helpers#^1.0.0",
     "paper-styles": "PolymerElements/paper-styles#^1.0.2",
     "web-component-tester": "^4.0.0",
     "webcomponentsjs": "webcomponents/webcomponentsjs#^0.7.0"
   },
   "ignore": []
 }