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

mojo/public/dart/third_party/collection/lib/collection.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.
+
+/**
+ * Exports all the individual parts of the collection-helper library.
+ *
+ * The sub-libraries of this package are:
+ *
+ * - `algorithms.dart`: Algorithms that work on lists (shuffle, binary search
+ *                      and various sorting algorithms).
+ * - `equality.dart`: Different notions of equality of collections.
+ * - `iterable_zip.dart`: Combining multiple iterables into one.
+ * - `priority_queue.dart`: Priority queue type and implementations.
+ * - `wrappers.dart`: Wrapper classes that delegate to a collection object.
+ *                    Includes unmodifiable views of collections.
+ */
+library dart.pkg.collection;
+
+export "algorithms.dart";
+export "equality.dart";
+export "iterable_zip.dart";
+export "priority_queue.dart";
+export "src/canonicalized_map.dart";
+export "src/queue_list.dart";
+export "wrappers.dart";