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

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

 
-class SVGMaskElementJs extends SVGElementJs implements SVGMaskElement native "*SVGMaskElement" {
+class _SVGMaskElementJs extends _SVGElementJs implements SVGMaskElement native "*SVGMaskElement" {
 
-  SVGAnimatedLengthJs get height() native "return this.height;";
+  _SVGAnimatedLengthJs get height() native "return this.height;";
 
-  SVGAnimatedEnumerationJs get maskContentUnits() native "return this.maskContentUnits;";
+  _SVGAnimatedEnumerationJs get maskContentUnits() native "return this.maskContentUnits;";
 
-  SVGAnimatedEnumerationJs get maskUnits() native "return this.maskUnits;";
+  _SVGAnimatedEnumerationJs get maskUnits() native "return this.maskUnits;";
 
-  SVGAnimatedLengthJs get width() native "return this.width;";
+  _SVGAnimatedLengthJs get width() native "return this.width;";
 
-  SVGAnimatedLengthJs get x() native "return this.x;";
+  _SVGAnimatedLengthJs get x() native "return this.x;";
 
-  SVGAnimatedLengthJs get y() native "return this.y;";
+  _SVGAnimatedLengthJs get y() native "return this.y;";
 
   // From SVGTests
 
-  SVGStringListJs get requiredExtensions() native "return this.requiredExtensions;";
+  _SVGStringListJs get requiredExtensions() native "return this.requiredExtensions;";
 
-  SVGStringListJs get requiredFeatures() native "return this.requiredFeatures;";
+  _SVGStringListJs get requiredFeatures() native "return this.requiredFeatures;";
 
-  SVGStringListJs get systemLanguage() native "return this.systemLanguage;";
+  _SVGStringListJs get systemLanguage() native "return this.systemLanguage;";
 
   bool hasExtension(String extension) native;
 
   // From SVGLangSpace
 
   String get xmllang() native "return this.xmllang;";
 
   void set xmllang(String value) native "this.xmllang = value;";
 
   String get xmlspace() native "return this.xmlspace;";
 
   void set xmlspace(String value) native "this.xmlspace = value;";
 
   // 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;
 }