UI flow rework for device reset options. Reset made available from gaia screen. Tests adapted.

chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h
index 34ad2be62642fb83134facc2faf8061c7fe08ecf..c208cb4ffe014fd3d78af3dace31bf08c3ffd7df 100644
--- a/chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h
@@ -51,9 +51,12 @@ class ResetScreenHandler : public ResetScreenActor,
  private:
   // JS messages handlers.
   void HandleOnCancel();
-  void HandleOnRestart(bool should_rollback);
+  void HandleOnRestart();
   void HandleOnPowerwash(bool rollback_checked);
   void HandleOnLearnMore();
+  void HandleOnShowRollback();
+  void HandleOnHideRollback();
+  void HandleOnShowConfirm();
 
   void ChooseAndApplyShowScenario();
   void ShowWithParams();
@@ -74,10 +77,13 @@ class ResetScreenHandler : public ResetScreenActor,
   // for first exec after boot situation.
   bool reboot_was_requested_;
 
-  // Keeps whether rollback option is available fo.
+  // Keeps whether rollback option is available.
   bool rollback_available_;
 
-  // Whether rollback is initiated.
+  // Keeps whether rollback option is active at the screen.
+  bool rollback_checked_;
+
+  // Whether rollback is initiated. Prevents screen-hide.
   bool preparing_for_rollback_;
 
   base::WeakPtrFactory<ResetScreenHandler> weak_ptr_factory_;