Removed unused ScreenObserver::OnSetUsernamePassword() method.

chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc

Index: chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc
diff --git a/chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc b/chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc
index e0fd8db09aa0b33e4d74b40e290e96c8748a8653..e3e8c80a9f04bd4569ada92d77c8fe3e57c00528 100644
--- a/chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc
+++ b/chrome/browser/chromeos/login/screens/device_disabled_screen_unittest.cc
@@ -45,8 +45,6 @@ class DeviceDisabledScreenTest : public testing::Test, public ScreenObserver {
   // ScreenObserver:
   MOCK_METHOD1(OnExit, void(ExitCodes));
   void ShowCurrentScreen() override;
-  void OnSetUserNamePassword(const std::string& username,
-                             const std::string& password) override;
   void SetHostConfiguration() override;
   void ConfigureHost(bool accepted_eula,
                      const std::string& lang,
@@ -97,11 +95,6 @@ void DeviceDisabledScreenTest::TearDown() {
 void DeviceDisabledScreenTest::ShowCurrentScreen() {
 }
 
-void DeviceDisabledScreenTest::OnSetUserNamePassword(
-    const std::string& username,
-    const std::string& password) {
-}
-
 void DeviceDisabledScreenTest::SetHostConfiguration() {
 }