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

mojo/public/dart/third_party/shelf_static/lib/src/util.dart

Index: mojo/public/dart/third_party/shelf_static/lib/src/util.dart
diff --git a/mojo/public/dart/third_party/shelf_static/lib/src/util.dart b/mojo/public/dart/third_party/shelf_static/lib/src/util.dart
new file mode 100644
index 0000000000000000000000000000000000000000..5db5e92b8e9645eb261b8f7a9b04cfbd6ddbf233
--- /dev/null
+++ b/mojo/public/dart/third_party/shelf_static/lib/src/util.dart
@@ -0,0 +1,10 @@
+// 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.
+
+library shelf_static.util;
+
+DateTime toSecondResolution(DateTime dt) {
+  if (dt.millisecond == 0) return dt;
+  return dt.subtract(new Duration(milliseconds: dt.millisecond));
+}