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

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

Index: client/dom/generated/src/frog/SVGPoint.dart
diff --git a/client/dom/generated/src/frog/SVGPoint.dart b/client/dom/generated/src/frog/SVGPoint.dart
index 6b8303cc647ee816c400578a2f00bf07c9c958ee..e4ac8c531eb4f8a754ad81c837e4d9d6460699fd 100644
--- a/client/dom/generated/src/frog/SVGPoint.dart
+++ b/client/dom/generated/src/frog/SVGPoint.dart
@@ -1,5 +1,5 @@
 
-class SVGPointJs extends DOMTypeJs implements SVGPoint native "*SVGPoint" {
+class _SVGPointJs extends _DOMTypeJs implements SVGPoint native "*SVGPoint" {
 
   num get x() native "return this.x;";
 
@@ -9,5 +9,5 @@ class SVGPointJs extends DOMTypeJs implements SVGPoint native "*SVGPoint" {
 
   void set y(num value) native "this.y = value;";
 
-  SVGPointJs matrixTransform(SVGMatrixJs matrix) native;
+  _SVGPointJs matrixTransform(_SVGMatrixJs matrix) native;
 }