Restore last used user session after crash

components/user_manager/user_manager.h

Index: components/user_manager/user_manager.h
diff --git a/components/user_manager/user_manager.h b/components/user_manager/user_manager.h
index e775279ba0a9bb91d0a0a09e1606b3ec7902ff8f..fb17de113c75cb3339f1c7806037bceb1ba1f09b 100644
--- a/components/user_manager/user_manager.h
+++ b/components/user_manager/user_manager.h
@@ -145,6 +145,10 @@ class USER_MANAGER_EXPORT UserManager {
   // Switches to active user identified by |user_id|. User has to be logged in.
   virtual void SwitchActiveUser(const std::string& user_id) = 0;
 
+  // Switches to the last active user (called after crash happens and session
+  // restore has completed).
+  virtual void SwitchToLastActiveUser() = 0;
+
   // Called when browser session is started i.e. after
   // browser_creator.LaunchBrowser(...) was called after user sign in.
   // When user is at the image screen IsUserLoggedIn() will return true