Define post reboot validation mode

components/chrome_cleaner/public/constants/constants.h

Index: components/chrome_cleaner/public/constants/constants.h
diff --git a/components/chrome_cleaner/public/constants/constants.h b/components/chrome_cleaner/public/constants/constants.h
index 551238d525469f6a9398402ce3d7ad2ced79e2ea..d31232ab52bbd7070e4edd035bbbda09cb5e9feb 100644
--- a/components/chrome_cleaner/public/constants/constants.h
+++ b/components/chrome_cleaner/public/constants/constants.h
@@ -110,6 +110,10 @@ enum class ExecutionMode {
   // user (UI handled by Chrome) and logs will only be uploaded if the user
   // opted into Extended Safe Browsing Reporting v2.
   kCleanup = 2,
+  // The cleaner will run in post-reboot validation mode. No UI will be shown
+  // to the user and logs will only be uploaded if the user opted into Extended
+  // Safe Browsing Reporting v2.
+  kPostRebootValidation = 3,
 };
 
 }  // namespace chrome_cleaner