Use different SDKs based on option settings

pkg/analysis_server/test/domain_execution_test.dart

Index: pkg/analysis_server/test/domain_execution_test.dart
diff --git a/pkg/analysis_server/test/domain_execution_test.dart b/pkg/analysis_server/test/domain_execution_test.dart
index a142adbea7e558faed0134d2170abb68e4aa1e34..1274eab6a8e02adcce02ecbdbca69b9e3b10404f 100644
--- a/pkg/analysis_server/test/domain_execution_test.dart
+++ b/pkg/analysis_server/test/domain_execution_test.dart
@@ -48,7 +48,7 @@ main() {
           null,
           serverPlugin,
           new AnalysisServerOptions(),
-          new MockSdk(),
+          () => new MockSdk(),
           InstrumentationService.NULL_SERVICE);
       handler = new ExecutionDomainHandler(server);
     });
@@ -124,8 +124,9 @@ main() {
 
       group('file to URI', () {
         test('does not exist', () {
-          Request request = new ExecutionMapUriParams(contextId,
-              file: '/a/c.dart').toRequest('2');
+          Request request =
+              new ExecutionMapUriParams(contextId, file: '/a/c.dart')
+                  .toRequest('2');
           Response response = handler.handleRequest(request);
           expect(response, isResponseFailure('2'));
         });
@@ -141,8 +142,9 @@ main() {
 
       group('URI to file', () {
         test('invalid', () {
-          Request request = new ExecutionMapUriParams(contextId,
-              uri: 'foo:///a/b.dart').toRequest('2');
+          Request request =
+              new ExecutionMapUriParams(contextId, uri: 'foo:///a/b.dart')
+                  .toRequest('2');
           Response response = handler.handleRequest(request);
           expect(response, isResponseFailure('2'));
         });
@@ -299,7 +301,7 @@ class ExecutionDomainTest extends AbstractAnalysisTest {
   }
 
   void test_mapUri_file_dartUriKind() {
-    String path = server.defaultSdk.mapDartUri('dart:async').fullName;
+    String path = server.findSdk().mapDartUri('dart:async').fullName;
     // hack - pretend that the SDK file exists in the project FS
     resourceProvider.newFile(path, '// hack');
     // map file