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

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

Index: client/dom/generated/src/frog/SVGTextPathElement.dart
diff --git a/client/dom/generated/src/frog/SVGTextPathElement.dart b/client/dom/generated/src/frog/SVGTextPathElement.dart
index c9a3c0c254b052956949d176b7aee93768f77133..d31fc7e728c9c3858a345b6419be102dc2999120 100644
--- a/client/dom/generated/src/frog/SVGTextPathElement.dart
+++ b/client/dom/generated/src/frog/SVGTextPathElement.dart
@@ -1,5 +1,5 @@
 
-class SVGTextPathElementJs extends SVGTextContentElementJs implements SVGTextPathElement native "*SVGTextPathElement" {
+class _SVGTextPathElementJs extends _SVGTextContentElementJs implements SVGTextPathElement native "*SVGTextPathElement" {
 
   static final int TEXTPATH_METHODTYPE_ALIGN = 1;
 
@@ -13,13 +13,13 @@ class SVGTextPathElementJs extends SVGTextContentElementJs implements SVGTextPat
 
   static final int TEXTPATH_SPACINGTYPE_UNKNOWN = 0;
 
-  SVGAnimatedEnumerationJs get method() native "return this.method;";
+  _SVGAnimatedEnumerationJs get method() native "return this.method;";
 
-  SVGAnimatedEnumerationJs get spacing() native "return this.spacing;";
+  _SVGAnimatedEnumerationJs get spacing() native "return this.spacing;";
 
-  SVGAnimatedLengthJs get startOffset() native "return this.startOffset;";
+  _SVGAnimatedLengthJs get startOffset() native "return this.startOffset;";
 
   // From SVGURIReference
 
-  SVGAnimatedStringJs get href() native "return this.href;";
+  _SVGAnimatedStringJs get href() native "return this.href;";
 }