Allow apidoc to skip MDN database.json entries that are bogus.

utils/apidoc/apidoc.dart

Index: utils/apidoc/apidoc.dart
===================================================================
--- utils/apidoc/apidoc.dart	(revision 11909)
+++ utils/apidoc/apidoc.dart	(working copy)
@@ -239,6 +239,12 @@
 
   static const disqusShortname = 'dartapidocs';
 
+  // A set of type names (TypeMirror.simpleName values) to ignore while
+  // looking up information from MDN data.  TODO(eub, jacobr): fix up the MDN
+  // import scripts so they run correctly and generate data that doesn't have
+  // any entries that need to be ignored.
+  static Set<String> _mdnTypeNamesToSkip = null;
+
   /**
    * The URL to the page on MDN that content was pulled from for the current
    * type being documented. Will be `null` if the type doesn't use any MDN
@@ -252,6 +258,11 @@
     this.mode = mode;
     this.generateAppCache = generateAppCache;
 
+    // Skip bad entries in the checked-in mdn/database.json:
+    //  * UnknownElement has a top-level Gecko DOM page in German.
+    if (_mdnTypeNamesToSkip == null)
+      _mdnTypeNamesToSkip = new Set.from(['UnknownElement']);
+
     mainTitle = 'Dart API Reference';
     mainUrl = 'http://dartlang.org';
 
@@ -448,6 +459,11 @@
    * scraped from MDN.
    */
   includeMdnTypeComment(TypeMirror type) {
+    if (_mdnTypeNamesToSkip.contains(type.simpleName)) {
+      print('Skipping MDN type ${type.simpleName}');
+      return null;
+    }
+
     var typeString = '';
     if (type.library.simpleName == HTML_LIBRARY_NAME) {
       // If it's an HTML type, try to map it to a base DOM type so we can find