Use "pub list-package-dirs" to resolve package URIs in analysis server.

pkg/analysis_server/test/domain_server_test.dart

Index: pkg/analysis_server/test/domain_server_test.dart
diff --git a/pkg/analysis_server/test/domain_server_test.dart b/pkg/analysis_server/test/domain_server_test.dart
index 58f9bbccda611eed4c343d1038aff668fd918a1f..7778ef0f08bf60348281d509de3ce84d845b371f 100644
--- a/pkg/analysis_server/test/domain_server_test.dart
+++ b/pkg/analysis_server/test/domain_server_test.dart
@@ -20,7 +20,8 @@ main() {
   setUp(() {
     var serverChannel = new MockServerChannel();
     var resourceProvider = PhysicalResourceProvider.INSTANCE;
-    server = new AnalysisServer(serverChannel, resourceProvider);
+    server = new AnalysisServer(
+        serverChannel, resourceProvider, new MockPackageMapProvider());
     handler = new ServerDomainHandler(server);
   });