Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

chrome/browser/chromeos/login/reauth_stats.cc

 // Copyright (c) 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 "chrome/browser/chromeos/login/reauth_stats.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "components/user_manager/known_user.h"
 
 namespace chromeos {
 
 void RecordReauthReason(const AccountId& account_id, ReauthReason reason) {
   int old_reason;
   // We record only the first value, skipping everything else, except "none"
   // value, which is used to reset the current state.
   if (!user_manager::known_user::FindReauthReason(account_id, &old_reason) ||
       (static_cast<ReauthReason>(old_reason) == ReauthReason::NONE &&
        reason != ReauthReason::NONE)) {
     user_manager::known_user::UpdateReauthReason(account_id,
                                                  static_cast<int>(reason));
   }
 }
 
 void SendReauthReason(const AccountId& account_id) {
-  int reauth_reason;
-  if (user_manager::known_user::FindReauthReason(account_id, &reauth_reason) &&
-      static_cast<ReauthReason>(reauth_reason) != ReauthReason::NONE) {
+  int reauth_reason_int;
+  if (!user_manager::known_user::FindReauthReason(account_id,
+                                                  &reauth_reason_int))
+    return;
+  ReauthReason reauth_reason = static_cast<ReauthReason>(reauth_reason_int);
+  if (reauth_reason != ReauthReason::NONE) {
     UMA_HISTOGRAM_ENUMERATION("Login.ReauthReason", reauth_reason,
                               NUM_REAUTH_FLOW_REASONS);
     user_manager::known_user::UpdateReauthReason(
         account_id, static_cast<int>(ReauthReason::NONE));
   }
 }
 
 }  // namespace chromeos