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

mojo/public/dart/third_party/crypto/test/hmac_sha256_test.dart

+// Copyright (c) 2012, 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 tag to allow the test to run on Dartium.
+library hmac_sha256_test;
+
+import "package:crypto/crypto.dart";
+import "package:test/test.dart";
+
+part 'hmac_sha256_test_vectors.dart';
+
+void main() {
+  test('standard vectors', () {
+    _testStandardVectors(hmac_sha256_inputs, hmac_sha256_keys,
+        hmac_sha256_macs);
+  });
+}
+
+void _testStandardVectors(inputs, keys, macs) {
+  for (var i = 0; i < inputs.length; i++) {
+    var hmac = new HMAC(new SHA256(), keys[i]);
+    hmac.add(inputs[i]);
+    var d = hmac.close();
+    expect(CryptoUtils.bytesToHex(d), startsWith(macs[i]));
+  }
+}