Use shared MockSdk instances in resynthesize tests.

pkg/analyzer/test/src/context/abstract_context.dart

Index: pkg/analyzer/test/src/context/abstract_context.dart
diff --git a/pkg/analyzer/test/src/context/abstract_context.dart b/pkg/analyzer/test/src/context/abstract_context.dart
index b0b7a01e321746b13216495c227d9e64de1f7559..be85eff96d447c1e3e1db1bdd20c973cc4532701 100644
--- a/pkg/analyzer/test/src/context/abstract_context.dart
+++ b/pkg/analyzer/test/src/context/abstract_context.dart
@@ -45,9 +45,12 @@ Element findChildElement(Element root, String name, [ElementKind kind]) {
 typedef void _ElementVisitorFunction(Element element);
 
 class AbstractContextTest {
+  static final MockSdk SHARED_MOCK_SDK = new MockSdk();
+  static final MockSdk SHARED_STRONG_MOCK_SDK = new MockSdk();
+
   MemoryResourceProvider resourceProvider = new MemoryResourceProvider();
 
-  DartSdk sdk = new MockSdk();
+  DartSdk sdk;
   SourceFactory sourceFactory;
   AnalysisContextImpl context;
   AnalysisCache analysisCache;
@@ -120,6 +123,8 @@ class AbstractContextTest {
     return new AnalysisContextImpl();
   }
 
+  DartSdk createDartSdk() => new MockSdk();

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

It seems strange to create a new SDK when we have two created above.

[scheglov, 2016/03/28 17:03:35]

My intention is to test SDK analysis from scratch in every Dart analysis task
test.
OTOH when we're outside of dart.dart tests, we can opt-in to using a shared SDK.

+
   Source newSource(String path, [String content = '']) {
     File file = resourceProvider.newFile(path, content);
     return file.createSource();
@@ -135,6 +140,7 @@ class AbstractContextTest {
   }
 
   void prepareAnalysisContext([AnalysisOptions options]) {
+    sdk = createDartSdk();
     sdkResolver = new DartUriResolver(sdk);
     resourceResolver = new ResourceUriResolver(resourceProvider);
     sourceFactory =