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

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

Index: client/dom/generated/src/frog/SVGGradientElement.dart
diff --git a/client/dom/generated/src/frog/SVGGradientElement.dart b/client/dom/generated/src/frog/SVGGradientElement.dart
index 3b87c94d8fc4b3ab5bf71cd36fd5aaf793b759eb..3fb93a5aa7a69acbb317f052abc8dc56529b6722 100644
--- a/client/dom/generated/src/frog/SVGGradientElement.dart
+++ b/client/dom/generated/src/frog/SVGGradientElement.dart
@@ -1,5 +1,5 @@
 
-class SVGGradientElementJs extends SVGElementJs implements SVGGradientElement native "*SVGGradientElement" {
+class _SVGGradientElementJs extends _SVGElementJs implements SVGGradientElement native "*SVGGradientElement" {
 
   static final int SVG_SPREADMETHOD_PAD = 1;
 
@@ -9,25 +9,25 @@ class SVGGradientElementJs extends SVGElementJs implements SVGGradientElement na
 
   static final int SVG_SPREADMETHOD_UNKNOWN = 0;
 
-  SVGAnimatedTransformListJs get gradientTransform() native "return this.gradientTransform;";
+  _SVGAnimatedTransformListJs get gradientTransform() native "return this.gradientTransform;";
 
-  SVGAnimatedEnumerationJs get gradientUnits() native "return this.gradientUnits;";
+  _SVGAnimatedEnumerationJs get gradientUnits() native "return this.gradientUnits;";
 
-  SVGAnimatedEnumerationJs get spreadMethod() native "return this.spreadMethod;";
+  _SVGAnimatedEnumerationJs get spreadMethod() native "return this.spreadMethod;";
 
   // From SVGURIReference
 
-  SVGAnimatedStringJs get href() native "return this.href;";
+  _SVGAnimatedStringJs get href() native "return this.href;";
 
   // 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;
 }