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

mojo/public/dart/third_party/stack_trace/lib/src/utils.dart

+// 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 stack_trace.src.utils;
+
+/// Returns [string] with enough spaces added to the end to make it [length]
+/// characters long.
+String padRight(String string, int length) {
+  if (string.length >= length) return string;
+
+  var result = new StringBuffer();
+  result.write(string);
+  for (var i = 0; i < length - string.length; i++) {
+    result.write(' ');
+  }
+
+  return result.toString();
+}
+
+/// Flattens nested lists inside an iterable into a single list containing only
+/// non-list elements.
+List flatten(Iterable nested) {
+  var result = [];
+  helper(list) {
+    for (var element in list) {
+      if (element is List) {
+        helper(element);
+      } else {
+        result.add(element);
+      }
+    }
+  }
+  helper(nested);
+  return result;
+}