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

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

Index: client/dom/generated/src/frog/SVGRadialGradientElement.dart
diff --git a/client/dom/generated/src/frog/SVGRadialGradientElement.dart b/client/dom/generated/src/frog/SVGRadialGradientElement.dart
index f7a5f6e95c2fbde92a8b8dbb84810766135e7f5c..4f70232d5c06b7dd62f835b9eb3ce82acdec4913 100644
--- a/client/dom/generated/src/frog/SVGRadialGradientElement.dart
+++ b/client/dom/generated/src/frog/SVGRadialGradientElement.dart
@@ -1,13 +1,13 @@
 
-class SVGRadialGradientElementJs extends SVGGradientElementJs implements SVGRadialGradientElement native "*SVGRadialGradientElement" {
+class _SVGRadialGradientElementJs extends _SVGGradientElementJs implements SVGRadialGradientElement native "*SVGRadialGradientElement" {
 
-  SVGAnimatedLengthJs get cx() native "return this.cx;";
+  _SVGAnimatedLengthJs get cx() native "return this.cx;";
 
-  SVGAnimatedLengthJs get cy() native "return this.cy;";
+  _SVGAnimatedLengthJs get cy() native "return this.cy;";
 
-  SVGAnimatedLengthJs get fx() native "return this.fx;";
+  _SVGAnimatedLengthJs get fx() native "return this.fx;";
 
-  SVGAnimatedLengthJs get fy() native "return this.fy;";
+  _SVGAnimatedLengthJs get fy() native "return this.fy;";
 
-  SVGAnimatedLengthJs get r() native "return this.r;";
+  _SVGAnimatedLengthJs get r() native "return this.r;";
 }