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

pkg/analysis_server/test/domain_analysis_test.dart

Index: pkg/analysis_server/test/domain_analysis_test.dart
diff --git a/pkg/analysis_server/test/domain_analysis_test.dart b/pkg/analysis_server/test/domain_analysis_test.dart
index d6375397317a4112fec735306695cab11c825a90..d12745be6e01ec12e80aee2b023f5cfb2db2672c 100644
--- a/pkg/analysis_server/test/domain_analysis_test.dart
+++ b/pkg/analysis_server/test/domain_analysis_test.dart
@@ -32,7 +32,8 @@ 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 AnalysisDomainHandler(server);
   });
@@ -209,7 +210,8 @@ class AnalysisTestHelper {
   AnalysisTestHelper() {
     serverChannel = new MockServerChannel();
     resourceProvider = new MemoryResourceProvider();
-    server = new AnalysisServer(serverChannel, resourceProvider);
+    server = new AnalysisServer(
+        serverChannel, resourceProvider, new MockPackageMapProvider());
     server.defaultSdk = new MockSdk();
     handler = new AnalysisDomainHandler(server);
     // listen for notifications
@@ -569,12 +571,14 @@ class AnalysisDomainTest extends AbstractAnalysisTest {
   }
 
   test_setRoots_packages() {
-    // prepare project with 'packages' folder
-    String pkgFile = '/project/packages/pkgA/libA.dart';
+    // prepare package
+    String pkgFile = '/packages/pkgA/libA.dart';
     resourceProvider.newFile(pkgFile, '''
 library lib_a;
 class A {}
 ''');
+    packageMapProvider.packageMap['pkgA'] =
+        resourceProvider.getResource('/packages/pkgA');
     addTestFile('''
 import 'package:pkgA/libA.dart';
 main(A a) {