Make dart:dom implementation types private so they don't muddle the docs.

client/dom/generated/src/frog/SVGNumberList.dart

Index: client/dom/generated/src/frog/SVGNumberList.dart
diff --git a/client/dom/generated/src/frog/SVGNumberList.dart b/client/dom/generated/src/frog/SVGNumberList.dart
index 73e6b334ee087e97c119686bfa6082c40b2afabb..092ac8555dc1ae634a2a7bc23b4760a3cecaf9e8 100644
--- a/client/dom/generated/src/frog/SVGNumberList.dart
+++ b/client/dom/generated/src/frog/SVGNumberList.dart
@@ -1,19 +1,19 @@
 
-class SVGNumberListJs extends DOMTypeJs implements SVGNumberList native "*SVGNumberList" {
+class _SVGNumberListJs extends _DOMTypeJs implements SVGNumberList native "*SVGNumberList" {
 
   int get numberOfItems() native "return this.numberOfItems;";
 
-  SVGNumberJs appendItem(SVGNumberJs item) native;
+  _SVGNumberJs appendItem(_SVGNumberJs item) native;
 
   void clear() native;
 
-  SVGNumberJs getItem(int index) native;
+  _SVGNumberJs getItem(int index) native;
 
-  SVGNumberJs initialize(SVGNumberJs item) native;
+  _SVGNumberJs initialize(_SVGNumberJs item) native;
 
-  SVGNumberJs insertItemBefore(SVGNumberJs item, int index) native;
+  _SVGNumberJs insertItemBefore(_SVGNumberJs item, int index) native;
 
-  SVGNumberJs removeItem(int index) native;
+  _SVGNumberJs removeItem(int index) native;
 
-  SVGNumberJs replaceItem(SVGNumberJs item, int index) native;
+  _SVGNumberJs replaceItem(_SVGNumberJs item, int index) native;
 }