mandoline filesystem: Save cookie data to the mojo:filesystem.

mojo/runner/scoped_user_data_dir.cc

+// Copyright 2015 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 "mojo/runner/scoped_user_data_dir.h"
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "mojo/runner/switches.h"
+
+namespace mojo {
+namespace runner {
+
+ScopedUserDataDir::ScopedUserDataDir() {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kUseTemporaryUserDataDir)) {
+    if (command_line->HasSwitch(switches::kUserDataDir)) {
+      LOG(ERROR) << "Can not have both --user-data-dir and "
+                 << "--use-temporary-user-data-dir in the same process.";
+      return;
+    }
+
+    if (!temp_dir_.CreateUniqueTempDir()) {
+      LOG(ERROR) << "Failed to create a temporary user data dir.";
+      return;
+    }
+
+    command_line->AppendSwitchPath(switches::kUserDataDir, temp_dir_.path());

[msw, 2015/06/24 23:00:35]

Heh, the irony here is that you're appending --user-data-dir after
--use-temporary-user-data-dir is detected, which violates the statement above.
(it's fine, but you may want to revise the error string or add a comment here)

+  }
+}
+
+ScopedUserDataDir::~ScopedUserDataDir() {
+}
+
+}  // namespace runner
+}  // namespace mojo