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

mojo/public/dart/third_party/package_config/test/all.dart

+// Copyright (c) 2015, 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.
+
+import "package:test/test.dart";
+
+import "discovery_analysis_test.dart" as discovery_analysis;
+import "discovery_test.dart" as discovery;
+import "parse_test.dart" as parse;
+import "parse_write_test.dart" as parse_write;
+
+main() {
+  group("parse:", parse.main);
+  group("discovery:", discovery.main);
+  group("discovery-analysis:", discovery_analysis.main);
+  group("parse/write:", parse_write.main);
+}