Add fallback behavior if the last used profile cannot initialize

chrome/browser/ui/startup/startup_browser_creator.h

Index: chrome/browser/ui/startup/startup_browser_creator.h
diff --git a/chrome/browser/ui/startup/startup_browser_creator.h b/chrome/browser/ui/startup/startup_browser_creator.h
index f2e3c0a5fd757609b5df07e3960161ba5350888d..1081c16ef8baf44e76f6044340ba7ada871918ed 100644
--- a/chrome/browser/ui/startup/startup_browser_creator.h
+++ b/chrome/browser/ui/startup/startup_browser_creator.h
@@ -179,4 +179,21 @@ bool HasPendingUncleanExit(Profile* profile);
 base::FilePath GetStartupProfilePath(const base::FilePath& user_data_dir,
                                      const base::CommandLine& command_line);
 
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
+// Returns the profile that should be loaded on process startup. This is either
+// the profile returned by GetStartupProfilePath, or the guest profile if the
+// above profile is locked. The guest profile denotes that we should open the
+// user manager. Returns null if the above profile cannot be opened. In case of
+// opening the user manager, returns null if either the guest profile or the
+// system profile cannot be opened.
+Profile* GetStartupProfile(const base::FilePath& user_data_dir,
+                           const base::CommandLine& command_line);
+
+// Returns the profile that should be loaded on process startup when
+// GetStartupProfile() returns null. As with GetStartupProfile(), returning the
+// guest profile means the caller should open the user manager. This may return
+// null if neither any profile nor the user manager can be opened.
+Profile* GetFallbackStartupProfile();
+#endif  // !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
+
 #endif  // CHROME_BROWSER_UI_STARTUP_STARTUP_BROWSER_CREATOR_H_