refactor: rename the atom directory to shell

shell/app/command_line_args.h

@@ -0,0 +1,16 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_APP_COMMAND_LINE_ARGS_H_
+#define ATOM_APP_COMMAND_LINE_ARGS_H_
+
+#include "base/command_line.h"
+
+namespace atom {
+
+bool CheckCommandLineArguments(int argc, base::CommandLine::CharType** argv);
+
+}  // namespace atom
+
+#endif  // ATOM_APP_COMMAND_LINE_ARGS_H_