polymer to support google on x

Author: btopro

polymer.json

@@ -5,6 +5,7 @@
     "node_modules/@polymer/app-layout/*/*.js",
     "node_modules/@polymer/**/*.js",
     "node_modules/@polymer/marked-element/node_modules/marked/lib/marked.js",
+    "node_modules/@google/model-viewer/dist/model-viewer.js",
     "node_modules/@vowo/chart-elements/*.js",
     "node_modules/intl-messageformat/src/*.js",
     "node_modules/intl-messageformat-parser/src/*.js",