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

pkg/analysis_server/test/domain_completion_test.dart

Index: pkg/analysis_server/test/domain_completion_test.dart
diff --git a/pkg/analysis_server/test/domain_completion_test.dart b/pkg/analysis_server/test/domain_completion_test.dart
index ad5be1fc76d623b53c92ee1c7d5154be08b1f0a1..aeb73d23a422c9ec72b6cfab7d8dd371949d03bb 100644
--- a/pkg/analysis_server/test/domain_completion_test.dart
+++ b/pkg/analysis_server/test/domain_completion_test.dart
@@ -24,7 +24,8 @@ main() {
   setUp(() {
     serverChannel = new MockServerChannel();
     resourceProvider = new MemoryResourceProvider();
-    server = new AnalysisServer(serverChannel, resourceProvider);
+    server = new AnalysisServer(
+        serverChannel, resourceProvider, new MockPackageMapProvider());
     server.defaultSdk = new MockSdk();
     handler = new CompletionDomainHandler(server);
   });