Use different SDKs based on option settings

pkg/analysis_server/test/analysis_server_test.dart

 // Copyright (c) 2014, 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 test.analysis_server;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/analysis_server.dart';
@@ skipping 123 matching lines @@
     channel = new MockServerChannel();
     resourceProvider = new MemoryResourceProvider();
     packageMapProvider = new MockPackageMapProvider();
     server = new AnalysisServer(
         channel,
         resourceProvider,
         packageMapProvider,
         null,
         new ServerPlugin(),
         new AnalysisServerOptions(),
-        new MockSdk(),
+        () => new MockSdk(),
         InstrumentationService.NULL_SERVICE,
         rethrowExceptions: true);
     processRequiredPlugins();
   }
 
   Future test_contextDisposed() {
     resourceProvider.newFolder('/foo');
     resourceProvider.newFile('/foo/bar.dart', 'library lib;');
     server.setAnalysisRoots('0', ['/foo'], [], {});
     AnalysisContext context;
-    return pumpEventQueue().then((_) {
-      context = server.getAnalysisContext('/foo/bar.dart');
-      server.setAnalysisRoots('1', [], [], {});
-    }).then((_) => pumpEventQueue()).then((_) {
-      expect(context.isDisposed, isTrue);
-    });
+    return pumpEventQueue()
+        .then((_) {
+          context = server.getAnalysisContext('/foo/bar.dart');
+          server.setAnalysisRoots('1', [], [], {});
+        })
+        .then((_) => pumpEventQueue())
+        .then((_) {
+          expect(context.isDisposed, isTrue);
+        });
   }
 
   Future test_contextsChangedEvent() {
     resourceProvider.newFolder('/foo');
 
     bool wasAdded = false;
     bool wasChanged = false;
     bool wasRemoved = false;
     server.onContextsChanged.listen((ContextsChangedEvent event) {
       wasAdded = event.added.length == 1;
@@ skipping 351 matching lines @@
     await pumpEventQueue();
     // the file has an overlay, so the file-system change was ignored
     expect(channel.notificationsReceived.any((notification) {
       return notification.event == SERVER_STATUS;
     }), isFalse);
   }
 
   void _assertContextOfFolder(
       AnalysisContext context, String expectedFolderPath) {
     Folder expectedFolder = resourceProvider.newFolder(expectedFolderPath);
-    ContextInfo expectedContextInfo = (server.contextManager
-        as ContextManagerImpl).getContextInfoFor(expectedFolder);
+    ContextInfo expectedContextInfo =
+        (server.contextManager as ContextManagerImpl)
+            .getContextInfoFor(expectedFolder);
     expect(expectedContextInfo, isNotNull);
     expect(context, same(expectedContextInfo.context));
   }
 
   void _configureSourceFactory(AnalysisContext context) {
     var resourceUriResolver = new ResourceUriResolver(resourceProvider);
     var packageUriResolver = new PackageMapUriResolver(
         resourceProvider, packageMapProvider.packageMap);
     context.sourceFactory =
         new SourceFactory([packageUriResolver, resourceUriResolver]);
@@ skipping 21 matching lines @@
   _MockServerOperation(this.context);
 
   @override
   ServerOperationPriority get priority => ServerOperationPriority.ANALYSIS;
 
   @override
   void perform(AnalysisServer server) {
     isComplete = true;
   }
 }