mojo: Fix leveldb unittests by making fs::Directories cloneable.

components/filesystem/shared_temp_dir.cc

Index: components/filesystem/shared_temp_dir.cc
diff --git a/components/filesystem/shared_temp_dir.cc b/components/filesystem/shared_temp_dir.cc
new file mode 100644
index 0000000000000000000000000000000000000000..375b8b8e9040ab705c6b9f293bc3dc262ada2a12
--- /dev/null
+++ b/components/filesystem/shared_temp_dir.cc
@@ -0,0 +1,16 @@
+// Copyright 2016 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.
+
+#include "components/filesystem/shared_temp_dir.h"
+
+#include "base/files/scoped_temp_dir.h"
+
+namespace filesystem {
+
+SharedTempDir::SharedTempDir(std::unique_ptr<base::ScopedTempDir> temp_dir)
+    : temp_dir_(std::move(temp_dir)) {}
+
+SharedTempDir::~SharedTempDir() {}
+
+}  // namespace filesystem