Replace the configuration map with a typed object.

tools/testing/dart/expectation_set.dart

 // Copyright (c) 2017, 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.
 
+import 'configuration.dart';
+import 'environment.dart';
 import 'expectation.dart';
 import 'status_file.dart';
 
 /// Tracks the [Expectation]s associated with a set of file paths.
 ///
 /// For any given file path, returns the expected test results for that file.
 /// A set can be loaded from a collection of status files. A file path may
 /// exist in multiple files (or even multiple sections within the file). When
 /// that happens, all of the expectations of every entry are combined.
 class ExpectationSet {
   /// Reads the expectations defined by the status files at [statusFilePaths]
-  /// given [environment].
+  /// when in [configuration].
   static ExpectationSet read(
-      List<String> statusFilePaths, Map<String, dynamic> environment) {
+      List<String> statusFilePaths, Configuration configuration) {
+    var environment = new Environment(configuration);
     var expectations = new ExpectationSet._();
     for (var path in statusFilePaths) {
       var file = new StatusFile.read(path);
       for (var section in file.sections) {
         if (section.isEnabled(environment)) {
           for (var entry in section.entries) {
             expectations.addEntry(entry);
           }
         }
       }
@@ skipping 80 matching lines @@
         var component = splitKey[i];
         var regExp = regExpCache.putIfAbsent(component,
             () => new RegExp("^${splitKey[i]}\$".replaceAll('*', '.*')));
         regExps[i] = regExp;
       }
 
       _keyToRegExps[key] = regExps;
     });
   }
 }