Use shared MockSdk instances in resynthesize tests.

pkg/analyzer/test/src/task/dart_test.dart

Index: pkg/analyzer/test/src/task/dart_test.dart
diff --git a/pkg/analyzer/test/src/task/dart_test.dart b/pkg/analyzer/test/src/task/dart_test.dart
index 205dc9055343dc66155dcf049f36c3c2d1568da3..c07689b09a01e81f099f6f991fcce682fe2c99c4 100644
--- a/pkg/analyzer/test/src/task/dart_test.dart
+++ b/pkg/analyzer/test/src/task/dart_test.dart
@@ -1076,17 +1076,14 @@ class BuildTypeProviderTaskTest extends _AbstractDartTaskTest {
 
 @reflectiveTest
 class BuildTypeProviderTaskTest_noAsync extends _AbstractDartTaskTest {
+  DartSdk createDartSdk() => new MockSdk(dartAsync: false);

[Brian Wilkerson, 2016/03/28 16:58:03]

Should this be a constant?

+
   void prepareAnalysisContext([AnalysisOptions options]) {
     AnalysisOptionsImpl newOptions = new AnalysisOptionsImpl();
     newOptions.enableAsync = false;
     super.prepareAnalysisContext(newOptions);
   }
 
-  void setUp() {
-    sdk = new MockSdk(dartAsync: false);
-    super.setUp();
-  }
-
   test_perform_noAsync() {
     expect(context, isNotNull);
     computeResult(AnalysisContextTarget.request, TYPE_PROVIDER,