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

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

 
-class CSSStyleDeclarationJs extends DOMTypeJs implements CSSStyleDeclaration native "*CSSStyleDeclaration" {
+class _CSSStyleDeclarationJs extends _DOMTypeJs implements CSSStyleDeclaration native "*CSSStyleDeclaration" {
 
   String get cssText() native "return this.cssText;";
 
   void set cssText(String value) native "this.cssText = value;";
 
   int get length() native "return this.length;";
 
-  CSSRuleJs get parentRule() native "return this.parentRule;";
+  _CSSRuleJs get parentRule() native "return this.parentRule;";
 
-  CSSValueJs getPropertyCSSValue(String propertyName) native;
+  _CSSValueJs getPropertyCSSValue(String propertyName) native;
 
   String getPropertyPriority(String propertyName) native;
 
   String getPropertyShorthand(String propertyName) native;
 
   String getPropertyValue(String propertyName) native;
 
   bool isPropertyImplicit(String propertyName) native;
 
   String item(int index) native;
 
   String removeProperty(String propertyName) native;
 
   void setProperty(String propertyName, String value, [String priority = null]) native;
 }