Convert ContextBuilder to use FolderBasedSdk

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

Index: pkg/analyzer/test/src/context/builder_test.dart
diff --git a/pkg/analyzer/test/src/context/builder_test.dart b/pkg/analyzer/test/src/context/builder_test.dart
index e6ed76f96d33d5bfff63525d72ebf6e90d053c30..cba70fa4088de307e836151a458e6ce79c8cdf03 100644
--- a/pkg/analyzer/test/src/context/builder_test.dart
+++ b/pkg/analyzer/test/src/context/builder_test.dart
@@ -457,7 +457,10 @@ class ContextBuilderTest_WithoutDisk extends EngineTestCase {
   @override
   void setUp() {
     resourceProvider = new MemoryResourceProvider();
-    sdkManager = new DartSdkManager('', false, (_) => new MockSdk());
+    new MockSdk(resourceProvider: resourceProvider);
+    sdkManager = new DartSdkManager('/', false, (_) {
+      fail('Should not be used to create an SDK');
+    });
     contentCache = new ContentCache();
     builder = new ContextBuilder(resourceProvider, sdkManager, contentCache);
   }