Remove uses of Path class from tests/standalone.

tests/standalone/io/web_socket_test.dart

Index: tests/standalone/io/web_socket_test.dart
diff --git a/tests/standalone/io/web_socket_test.dart b/tests/standalone/io/web_socket_test.dart
index 96db48347b347ca1c370d561549d6b38c5e8e40e..d129354640cd65e75c23eb4689a389bf1a85f04a 100644
--- a/tests/standalone/io/web_socket_test.dart
+++ b/tests/standalone/io/web_socket_test.dart
@@ -8,6 +8,7 @@
 // VMOptions=--short_socket_read --short_socket_write
 
 import "package:expect/expect.dart";
+import "package:path/path.dart";
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
@@ -404,9 +405,8 @@ class SecurityConfiguration {
 
 
 void initializeSSL() {
-  var testPkcertDatabase =
-      new Path(Platform.script).directoryPath.append("pkcert/");
-  SecureSocket.initialize(database: testPkcertDatabase.toNativePath(),
+  var testPkcertDatabase = join(dirname(Platform.script), 'pkcert');
+  SecureSocket.initialize(database: testPkcertDatabase,
                           password: "dartdart");
 }