[Sync] Fixing easy lint violations.

components/sync/core/test/test_user_share.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A handy class that takes care of setting up and destroying a
 // UserShare instance for unit tests that require one.
 //
 // The expected usage is to make this a component of your test fixture:
 //
 //   class AwesomenessTest : public testing::Test {
@@ skipping 14 matching lines @@
 //     ReadTransaction trans(test_user_share_.user_share());
 //     ...
 //   }
 //
 
 #ifndef COMPONENTS_SYNC_CORE_TEST_TEST_USER_SHARE_H_
 #define COMPONENTS_SYNC_CORE_TEST_TEST_USER_SHARE_H_
 
 #include <stddef.h>
 
+#include <memory>
+
 #include "base/macros.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/core/user_share.h"
 
 namespace syncer {
 
 class SyncEncryptionHandler;
 class TestDirectorySetterUpper;
 
 namespace syncable {
@@ skipping 37 matching lines @@
  private:
   std::unique_ptr<TestDirectorySetterUpper> dir_maker_;
   std::unique_ptr<UserShare> user_share_;
 
   DISALLOW_COPY_AND_ASSIGN(TestUserShare);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_CORE_TEST_TEST_USER_SHARE_H_