Update charted to 0.4.8 and roll

packages/web_components/lib/ShadowDOM.js

Index: packages/web_components/lib/ShadowDOM.js
diff --git a/packages/web_components/lib/ShadowDOM.js b/packages/web_components/lib/ShadowDOM.js
old mode 100644
new mode 100755
index 14565b2a20341bf4df7b884431406d890027bff4..cb20a25998cfdd6a2325406d6c910ea397bfce13
--- a/packages/web_components/lib/ShadowDOM.js
+++ b/packages/web_components/lib/ShadowDOM.js
@@ -7,7 +7,7 @@
  * Code distributed by Google as part of the polymer project is also
  * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
  */
-// @version 0.7.21
+// @version 0.7.23
 if (typeof WeakMap === "undefined") {
   (function() {
     var defineProperty = Object.defineProperty;
@@ -165,6 +165,9 @@ window.ShadowDOMPolyfill = {};
   }
   function getDescriptor(source, name) {
     try {
+      if (source === window && name === "showModalDialog") {
+        return dummyDescriptor;
+      }
       return Object.getOwnPropertyDescriptor(source, name);
     } catch (ex) {
       return dummyDescriptor;