Move file_system libraries into 'analyzer'.

pkg/analysis_server/test/package_uri_resolver_test.dart

Index: pkg/analysis_server/test/package_uri_resolver_test.dart
diff --git a/pkg/analysis_server/test/package_uri_resolver_test.dart b/pkg/analysis_server/test/package_uri_resolver_test.dart
index e9c6e281ab04f5f61396a0dd02bf56cec7d9f178..a445239dbef328ae0892eaf76fed597b52817807 100644
--- a/pkg/analysis_server/test/package_uri_resolver_test.dart
+++ b/pkg/analysis_server/test/package_uri_resolver_test.dart
@@ -7,7 +7,8 @@ library test.resolver.package;
 import 'dart:collection';
 
 import 'package:analysis_server/src/package_uri_resolver.dart';
-import 'package:analysis_server/src/resource.dart';
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
@@ -33,12 +34,6 @@ class _PackageMapUriResolverTest {
   tearDown() {
   }
 
-  void test_isPackageUri() {
-    Uri uri = Uri.parse('package:test/test.dart');
-    expect(uri.scheme, 'package');
-    expect(PackageMapUriResolver.isPackageUri(uri), isTrue);
-  }
-
   void test_fromEncoding_nonPackage() {
     UriResolver resolver = new PackageMapUriResolver(provider, EMPTY_MAP);
     Uri uri = Uri.parse('file:/does/not/exist.dart');
@@ -54,6 +49,12 @@ class _PackageMapUriResolverTest {
     expect(result.fullName, '/does/not/exist.dart');
   }
 
+  void test_isPackageUri() {
+    Uri uri = Uri.parse('package:test/test.dart');
+    expect(uri.scheme, 'package');
+    expect(PackageMapUriResolver.isPackageUri(uri), isTrue);
+  }
+
   void test_isPackageUri_null_scheme() {
     Uri uri = Uri.parse('foo.dart');
     expect(uri.scheme, '');