cros: Break BaseScreenHandler into two classes.

chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc
index e38c74c4f4e3bc1518e6a723221aa28ea9807e1a..87b19203204d5573ccffee6f0c3625bf919d79e4 100644
--- a/chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/wrong_hwid_screen_handler.cc
@@ -16,7 +16,8 @@ const char kJsScreenPath[] = "login.WrongHWIDScreen";
 
 namespace chromeos {
 
-WrongHWIDScreenHandler::WrongHWIDScreenHandler() {
+WrongHWIDScreenHandler::WrongHWIDScreenHandler()
+    : BaseScreenHandler(kScreenId) {
   set_call_js_prefix(kJsScreenPath);
 }
 
@@ -30,7 +31,7 @@ void WrongHWIDScreenHandler::Show() {
     show_on_init_ = true;
     return;
   }
-  ShowScreen(OobeScreen::SCREEN_WRONG_HWID);
+  ShowScreen(kScreenId);
 }
 
 void WrongHWIDScreenHandler::Hide() {