Use fields in hidden native DOM classes instead of getters/setters.

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

Index: client/dom/generated/src/frog/Console.dart
diff --git a/client/dom/generated/src/frog/Console.dart b/client/dom/generated/src/frog/Console.dart
index a197d134579b7346f5b71e4718ada305cd7b0dd9..2368ae82b9a7604b5612444629edf08e804a1116 100644
--- a/client/dom/generated/src/frog/Console.dart
+++ b/client/dom/generated/src/frog/Console.dart
@@ -9,9 +9,9 @@ class _ConsoleJs
     implements Console, DOMType
     native "=(typeof console == 'undefined' ? {} : console)" {
 
-  _MemoryInfoJs get memory() native "return this.memory;";
+  final _MemoryInfoJs memory;
 
-  List get profiles() native "return this.profiles;";
+  final List profiles;
 
   void assertCondition(bool condition) native;