Renamed some scoping classes to make their usage clearer.

tests/compiler/dart2js/serialization/model_test_helper.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.serialization_model_test;
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/closure.dart';
@@ skipping 234 matching lines @@
   if (a is ClosureFieldElement && b is ClosureFieldElement) {
     return areElementsEquivalent(a.closureClass, b.closureClass) &&
         areLocalsEquivalent(a.local, b.local);
   } else if (a is BoxFieldElement && b is BoxFieldElement) {
     return areElementsEquivalent(a.variableElement, b.variableElement) &&
         areLocalsEquivalent(a.box, b.box);
   }
   return false;
 }
 
-bool areClosureScopesEquivalent(ClosureScope a, ClosureScope b) {
+bool areCapturedScopesEquivalent(CapturedScope a, CapturedScope b) {
   if (a == b) return true;
   if (a == null || b == null) return false;
   if (!areLocalsEquivalent(a.context, b.context)) {
     return false;
   }
   if (!areLocalsEquivalent(a.thisLocal, b.thisLocal)) {
     return false;
   }
   var aBoxed = {};
   a.forEachBoxedVariable((k, v) => aBoxed[k] = v);
   var bBoxed = {};
   b.forEachBoxedVariable((k, v) => bBoxed[k] = v);
-  checkMaps(aBoxed, bBoxed, 'ClosureScope.boxedVariables', areLocalsEquivalent,
+  checkMaps(aBoxed, bBoxed, 'CapturedScope.boxedVariables', areLocalsEquivalent,
       areElementsEquivalent);
   return true;
 }
 
 String nodeToString(Node node) {
   String text = '$node';
   if (text.length > 40) {
     return '(${node.runtimeType}) ${text.substring(0, 37)}...';
   }
   return '(${node.runtimeType}) $text';
@@ skipping 14 matching lines @@
   check(outputUnit1, outputUnit2, 'OutputUnit.isMainOutput $message',
       outputUnit1.isMainOutput, outputUnit2.isMainOutput);
   checkSetEquivalence(
       outputUnit1,
       outputUnit2,
       'OutputUnit.imports $message',
       outputUnit1.imports,
       outputUnit2.imports,
       (a, b) => areElementsEquivalent(a.declaration, b.declaration));
 }