Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/analyzer/test/utils.dart

Index: mojo/public/dart/third_party/analyzer/test/utils.dart
diff --git a/mojo/public/dart/third_party/analyzer/test/utils.dart b/mojo/public/dart/third_party/analyzer/test/utils.dart
new file mode 100644
index 0000000000000000000000000000000000000000..7c9fbe01d274542be37c6747da69fa145036ff6b
--- /dev/null
+++ b/mojo/public/dart/third_party/analyzer/test/utils.dart
@@ -0,0 +1,14 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library analyzer.test.utils;
+
+import 'package:analyzer/src/generated/java_io.dart';
+import 'package:path/path.dart' as path;
+import 'package:unittest/unittest.dart';
+
+void initializeTestEnvironment() {
+  groupSep = ' | ';
+  JavaFile.pathContext = path.posix;
+}