Roll Dart forward and use the shared vmservice isolate sources + benchmark fixes

mojo/dart/embedder/vmservice/loader.dart

Index: mojo/dart/embedder/vmservice/loader.dart
diff --git a/mojo/dart/embedder/vmservice/loader.dart b/mojo/dart/embedder/vmservice/loader.dart
deleted file mode 100644
index a8d0d94d53235ce78ac2ed9062845fea73c32576..0000000000000000000000000000000000000000
--- a/mojo/dart/embedder/vmservice/loader.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-part of dart_controller_service_isolate;
-
-_processLoadRequest(request) {
-  var sp = request[0];
-  var uri = Uri.parse(request[1]);
-  sp.send('Service isolate loading not supported by embedder (uri = $uri).');
-}