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

components/login/secure_module_util_chromeos.cc

Index: components/login/secure_module_util_chromeos.cc
diff --git a/components/login/secure_module_util_chromeos.cc b/components/login/secure_module_util_chromeos.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b33ef168cffd7f03e59bcd0a6291c2fdbe674071
--- /dev/null
+++ b/components/login/secure_module_util_chromeos.cc
@@ -0,0 +1,48 @@
+// 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.
+
+#include "components/login/secure_module_util_chromeos.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/task_scheduler/post_task.h"
+
+namespace login {
+
+namespace {
+
+// If either of these two files exist, then we are using Cr50 and not using TPM.
+constexpr char kCr50UsedIndicatorFile1[] =
+    "/opt/google/cr50/firmware/cr50.bin.prod";
+constexpr char kCr50UsedIndicatorFile2[] = "/etc/init/cr50-update.conf";
+
+SecureModuleUsed g_secure_module_used = SecureModuleUsed::UNQUERIED;
+
+SecureModuleUsed GetSecureModuleInfoFromFilesAndCacheIt() {
+  if (base::PathExists(base::FilePath(kCr50UsedIndicatorFile1)) ||
+      base::PathExists(base::FilePath(kCr50UsedIndicatorFile2))) {
+    g_secure_module_used = SecureModuleUsed::CR50;
+  } else {
+    g_secure_module_used = SecureModuleUsed::TPM;
+  }
+  return g_secure_module_used;
+}
+
+}  // namespace
+
+void GetSecureModuleUsed(GetSecureModuleUsedCallback callback) {
+  if (g_secure_module_used != SecureModuleUsed::UNQUERIED) {
+    base::ResetAndReturn(&callback).Run(g_secure_module_used);
+    return;
+  }
+
+  base::PostTaskWithTraitsAndReplyWithResult(
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
+      base::BindOnce(&GetSecureModuleInfoFromFilesAndCacheIt),
+      std::move(callback));
+}
+
+}  // namespace login