Start separating ClassElementImpl for Class and Enum.

pkg/analyzer/lib/src/generated/testing/element_factory.dart

Index: pkg/analyzer/lib/src/generated/testing/element_factory.dart
diff --git a/pkg/analyzer/lib/src/generated/testing/element_factory.dart b/pkg/analyzer/lib/src/generated/testing/element_factory.dart
index cfa6c85325ce06b27f7cb8afc1550bea7b392484..1b0ec835019560e385d9cefd9c1786b7edea7436 100644
--- a/pkg/analyzer/lib/src/generated/testing/element_factory.dart
+++ b/pkg/analyzer/lib/src/generated/testing/element_factory.dart
@@ -44,7 +44,7 @@ class ElementFactory {
   static ClassElementImpl classElement(
       String typeName, InterfaceType superclassType,
       [List<String> parameterNames]) {
-    ClassElementImpl element = new ClassElementImpl(typeName, 0);
+    ClassElementImpl element = new ClassElementImpl_Class(typeName, 0);
     element.constructors = const <ConstructorElement>[];
     element.supertype = superclassType;
     InterfaceTypeImpl type = new InterfaceTypeImpl(element);
@@ -143,11 +143,10 @@ class ElementFactory {
     //
     // Build the enum.
     //
-    ClassElementImpl enumElement = new ClassElementImpl(enumName, -1);
+    ClassElementImpl enumElement = new ClassElementImpl_Enum(enumName, -1);
     InterfaceTypeImpl enumType = new InterfaceTypeImpl(enumElement);
     enumElement.type = enumType;
     enumElement.supertype = objectType;
-    enumElement.enum2 = true;
     //
     // Populate the fields.
     //