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

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

Index: client/dom/generated/src/frog/SVGSymbolElement.dart
diff --git a/client/dom/generated/src/frog/SVGSymbolElement.dart b/client/dom/generated/src/frog/SVGSymbolElement.dart
index 42d211974f5856148e30c4aea9625c030825c854..40d47176b2aa6093a4cb9a6136236c58f11a8a4e 100644
--- a/client/dom/generated/src/frog/SVGSymbolElement.dart
+++ b/client/dom/generated/src/frog/SVGSymbolElement.dart
@@ -1,5 +1,5 @@
 
-class SVGSymbolElementJs extends SVGElementJs implements SVGSymbolElement native "*SVGSymbolElement" {
+class _SVGSymbolElementJs extends _SVGElementJs implements SVGSymbolElement native "*SVGSymbolElement" {
 
   // From SVGLangSpace
 
@@ -13,19 +13,19 @@ class SVGSymbolElementJs extends SVGElementJs implements SVGSymbolElement native
 
   // From SVGExternalResourcesRequired
 
-  SVGAnimatedBooleanJs get externalResourcesRequired() native "return this.externalResourcesRequired;";
+  _SVGAnimatedBooleanJs get externalResourcesRequired() native "return this.externalResourcesRequired;";
 
   // From SVGStylable
 
-  SVGAnimatedStringJs get className() native "return this.className;";
+  _SVGAnimatedStringJs get className() native "return this.className;";
 
-  CSSStyleDeclarationJs get style() native "return this.style;";
+  _CSSStyleDeclarationJs get style() native "return this.style;";
 
-  CSSValueJs getPresentationAttribute(String name) native;
+  _CSSValueJs getPresentationAttribute(String name) native;
 
   // From SVGFitToViewBox
 
-  SVGAnimatedPreserveAspectRatioJs get preserveAspectRatio() native "return this.preserveAspectRatio;";
+  _SVGAnimatedPreserveAspectRatioJs get preserveAspectRatio() native "return this.preserveAspectRatio;";
 
-  SVGAnimatedRectJs get viewBox() native "return this.viewBox;";
+  _SVGAnimatedRectJs get viewBox() native "return this.viewBox;";
 }