cros: Replace "TPM" with "secure module" for machines without TPM.

components/login/secure_module_util_chromeos.h

Index: components/login/secure_module_util_chromeos.h
diff --git a/components/login/secure_module_util_chromeos.h b/components/login/secure_module_util_chromeos.h
new file mode 100644
index 0000000000000000000000000000000000000000..424e2bb412fc74c12283a948fa45a6f4b11cd7ac
--- /dev/null
+++ b/components/login/secure_module_util_chromeos.h
@@ -0,0 +1,29 @@
+// Copyright 2017 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.
+
+#ifndef COMPONENTS_LOGIN_SECURE_MODULE_UTIL_H_
+#define COMPONENTS_LOGIN_SECURE_MODULE_UTIL_H_
+
+#include "base/callback.h"
+#include "components/login/login_export.h"
+
+namespace login {
+
+enum class SecureModuleUsed {
+  UNQUERIED,
+  CR50,
+  TPM,
+};
+
+// Receives one argument which contains the type of secure module we are using.
+using GetSecureModuleUsedCallback =
+    base::OnceCallback<void(SecureModuleUsed secure_module)>;
+
+// Gets the secure module by checking for certain files on the filesystem or in
+// the cache. |callback| is called with type of secure module we are using.
+void LOGIN_EXPORT GetSecureModuleUsed(GetSecureModuleUsedCallback callback);
+
+}  // namespace login
+
+#endif  // COMPONENTS_LOGIN_SECURE_MODULE_UTIL_H_