Get rid of DOMWrapperBase and DOMTypeBase.

lib/dom/src/native_DOMImplementation.dart

Index: lib/dom/src/native_DOMImplementation.dart
diff --git a/lib/dom/src/native_DOMImplementation.dart b/lib/dom/src/native_DOMImplementation.dart
index c9e98d0278e72b2831db4747690c411ecdfeeac6..a66e019ea9fa89afcc2d98a986c25c79a3a85c28 100644
--- a/lib/dom/src/native_DOMImplementation.dart
+++ b/lib/dom/src/native_DOMImplementation.dart
@@ -37,14 +37,14 @@ class _Utils {
 
 Utils_print(String message) native "Utils_print";
 
-class _NPObject extends _DOMWrapperBase {
+class _NPObject extends NativeFieldWrapperClass1 {
   _NPObject();
   static _NPObject retrieve(String key) native "NPObject_retrieve";
   property(String propertyName) native "NPObject_property";
   invoke(String methodName, [ObjectArray args = null]) native "NPObject_invoke";
 }
 
-class _DOMWindowCrossFrameImpl extends _DOMWrapperBase implements Window {
+class _DOMWindowCrossFrameImpl extends NativeFieldWrapperClass1 implements Window {
   _DOMWindowCrossFrameImpl();
 
   // Fields.
@@ -66,7 +66,7 @@ class _DOMWindowCrossFrameImpl extends _DOMWrapperBase implements Window {
   String get typeName() => "DOMWindow";
 }
 
-class _HistoryCrossFrameImpl extends _DOMWrapperBase implements History {
+class _HistoryCrossFrameImpl extends NativeFieldWrapperClass1 implements History {
   _HistoryCrossFrameImpl();
 
   // Methods.
@@ -78,7 +78,7 @@ class _HistoryCrossFrameImpl extends _DOMWrapperBase implements History {
   String get typeName() => "History";
 }
 
-class _LocationCrossFrameImpl extends _DOMWrapperBase implements Location {
+class _LocationCrossFrameImpl extends NativeFieldWrapperClass1 implements Location {
   _LocationCrossFrameImpl();
 
   // Fields.