Update Polymer components.

third_party/polymer/components/iron-menu-behavior/.bower.json

Index: third_party/polymer/components/iron-menu-behavior/.bower.json
diff --git a/third_party/polymer/components/iron-menu-behavior/.bower.json b/third_party/polymer/components/iron-menu-behavior/.bower.json
index 1481537655c978f65cc58194a1045c0f82428bc2..704911bd9e89b768bdb3ed46457597a962b33fe4 100644
--- a/third_party/polymer/components/iron-menu-behavior/.bower.json
+++ b/third_party/polymer/components/iron-menu-behavior/.bower.json
@@ -1,6 +1,6 @@
 {
   "name": "iron-menu-behavior",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "Provides accessible menu behavior",
   "authors": "The Polymer Authors",
   "keywords": [
@@ -34,11 +34,11 @@
     "web-component-tester": "^4.0.0",
     "webcomponentsjs": "webcomponents/webcomponentsjs#^0.7.0"
   },
-  "_release": "1.3.0",
+  "_release": "1.3.1",
   "_resolution": {
     "type": "version",
-    "tag": "v1.3.0",
-    "commit": "707791b8166d9233a582fee5b2df0f6eaea40973"
+    "tag": "v1.3.1",
+    "commit": "e5222093effd1637d6f2453005cf18a2e31552f7"
   },
   "_source": "https://github.com/PolymerElements/iron-menu-behavior.git",
   "_target": "^1.0.0",