Fix regression for import suggestions

pkg/analysis_server/test/analysis_abstract.dart

Index: pkg/analysis_server/test/analysis_abstract.dart
diff --git a/pkg/analysis_server/test/analysis_abstract.dart b/pkg/analysis_server/test/analysis_abstract.dart
index 8286482bca0d77ea29fe27d3efc68c23b4d2da6c..a0aae0125d79723c881831bd07f340abf3a70bb0 100644
--- a/pkg/analysis_server/test/analysis_abstract.dart
+++ b/pkg/analysis_server/test/analysis_abstract.dart
@@ -64,6 +64,9 @@ class AbstractAnalysisTest {
 
   AbstractAnalysisTest();
 
+  AnalysisDomainHandler get analysisHandler => server.handlers
+      .singleWhere((handler) => handler is AnalysisDomainHandler);
+
   void addAnalysisSubscription(AnalysisService service, String file) {
     // add file to subscription
     var files = analysisSubscriptions[service];
@@ -143,7 +146,7 @@ class AbstractAnalysisTest {
     resourceProvider.newFolder(projectPath);
     Request request =
         new AnalysisSetAnalysisRootsParams([projectPath], []).toRequest('0');
-    handleSuccessfulRequest(request);
+    handleSuccessfulRequest(request, handler: analysisHandler);
   }
 
   /**
@@ -171,7 +174,8 @@ class AbstractAnalysisTest {
   /**
    * Validates that the given [request] is handled successfully.
    */
-  Response handleSuccessfulRequest(Request request) {
+  Response handleSuccessfulRequest(Request request, {RequestHandler handler}) {
+    handler ??= this.handler;
     Response response = handler.handleRequest(request);
     expect(response, isResponseSuccess(request.id));
     return response;
@@ -203,8 +207,7 @@ class AbstractAnalysisTest {
     packageMapProvider = new MockPackageMapProvider();
     Index index = createIndex();
     server = createAnalysisServer(index);
-    handler = server.handlers
-        .singleWhere((handler) => handler is AnalysisDomainHandler);
+    handler = analysisHandler;
     // listen for notifications
     Stream<Notification> notificationStream =
         serverChannel.notificationController.stream;