Refactor Library/CompilationUnit and how we define local Scope.

tests/compiler/dart2js/find_my_name_test.dart

Index: tests/compiler/dart2js/find_my_name_test.dart
diff --git a/tests/compiler/dart2js/find_my_name_test.dart b/tests/compiler/dart2js/find_my_name_test.dart
index 8f9322343c1dd9b1b63cf0f87b6985fd826f34b3..008575d70089df52f139ddf3107334c9302a6e6c 100644
--- a/tests/compiler/dart2js/find_my_name_test.dart
+++ b/tests/compiler/dart2js/find_my_name_test.dart
@@ -17,7 +17,7 @@ class Foo {
 
   ClassElement foo = parseUnit(code, compiler, compiler.mainApp).head;
   foo.parseNode(compiler);
-  for (Element e in foo.localMembers.getValues()) {
+  for (Element e in foo.localMembers) {
     // TODO(ahe): Should test for e.name.slowToString() instead.
     Expect.equals(code.indexOf('operator+'), e.position().charOffset);
   }