mojo api for view based lockscreen

chrome/browser/chromeos/login/lock/screen_locker.cc

Index: chrome/browser/chromeos/login/lock/screen_locker.cc
diff --git a/chrome/browser/chromeos/login/lock/screen_locker.cc b/chrome/browser/chromeos/login/lock/screen_locker.cc
index e0b05e96e74706aa3dc4f823345f830c464ae105..9bbb939ab0c511741dbf4243c1d2d3b4e8c8cec9 100644
--- a/chrome/browser/chromeos/login/lock/screen_locker.cc
+++ b/chrome/browser/chromeos/login/lock/screen_locker.cc
@@ -42,6 +42,7 @@
 #include "chrome/browser/signin/easy_unlock_service.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/ui/ash/ash_util.h"
+#include "chrome/browser/ui/ash/lock_screen_client_chromeos.h"
 #include "chrome/browser/ui/ash/session_controller_client.h"
 #include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h"
 #include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h"
@@ -175,7 +176,8 @@ class StubDelegate : public ScreenLocker::Delegate {
   void SetPasswordInputEnabled(bool enabled) override { NOTIMPLEMENTED(); }
   void ShowErrorMessage(int error_msg_id,
                         HelpAppLauncher::HelpTopic help_topic_id) override {
-    NOTIMPLEMENTED();
+    // TODO(xiaoyinh): Complete the implementation here.
+    LockScreenClientChromeOS::Get()->ShowErrorMessage();
   }
   void ClearErrors() override { NOTIMPLEMENTED(); }
   void AnimateAuthenticationSuccess() override { NOTIMPLEMENTED(); }