cros: HTML fixes needed to reinitializing an existing lock WebUI.

chrome/browser/chromeos/login/signin_screen_controller.h

Index: chrome/browser/chromeos/login/signin_screen_controller.h
diff --git a/chrome/browser/chromeos/login/signin_screen_controller.h b/chrome/browser/chromeos/login/signin_screen_controller.h
index 6b95adc41d9ab006525c83c72884e2399514cc84..b60cb2f53c4706cadff04919a339fa3cdae235b0 100644
--- a/chrome/browser/chromeos/login/signin_screen_controller.h
+++ b/chrome/browser/chromeos/login/signin_screen_controller.h
@@ -23,6 +23,10 @@ class OobeUI;
 
 // Class that manages control flow between wizard screens. Wizard controller
 // interacts with screen controllers to move the user between screens.
+//
+// This class is allocated when the signin or lock screen is actually visible to
+// the user. It is a 'per-session' class; SignInScreenHandler, in comparsion, is
+// tied to the WebContents lifetime and therefore may live beyond this class.
 class SignInScreenController : public user_manager::RemoveUserDelegate,
                                public content::NotificationObserver {
  public: