Add some special screens in views login screen part 2

Add the following screens:
1. ShowErrorScreen
2. ShowSigninUI

Bug: 828058
Change-Id: Id632fd49b4e1575ad5443b5f315067bdbe08efd9
Reviewed-on: https://chromium-review.googlesource.com/1098457Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Xiaoyin Hu <xiaoyinh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567011}

chrome/browser/chromeos/login/ui/login_display_host_mojo.cc

@@ -78,6 +78,18 @@ void LoginDisplayHostMojo::ShowUnrecoverableCrypthomeErrorDialog() {
   dialog_->Show(false /*closable_by_esc*/);
 }
 
+void LoginDisplayHostMojo::ShowErrorScreen(LoginDisplay::SigninError error_id) {
+  DCHECK(GetOobeUI());
+  GetOobeUI()->signin_screen_handler()->ShowErrorScreen(error_id);
+  dialog_->Show(false /*closable_by_esc*/);
+}
+
+void LoginDisplayHostMojo::ShowSigninUI(const std::string& email) {
+  DCHECK(GetOobeUI());
+  GetOobeUI()->signin_screen_handler()->ShowSigninUI(email);
+  dialog_->Show(true /*closable_by_esc*/);
+}
+
 LoginDisplay* LoginDisplayHostMojo::CreateLoginDisplay(
     LoginDisplay::Delegate* delegate) {
   user_selection_screen_->SetLoginDisplayDelegate(delegate);

chrome/browser/chromeos/login/ui/login_display_host_mojo.h

@@ -49,6 +49,12 @@ class LoginDisplayHostMojo : public LoginDisplayHostCommon,
   // Show unrecoverable cryptohome error dialog.
   void ShowUnrecoverableCrypthomeErrorDialog();
 
+  // Displays detailed error screen for error with ID |error_id|.
+  void ShowErrorScreen(LoginDisplay::SigninError error_id);
+
+  // Shows signin UI with specified email.
+  void ShowSigninUI(const std::string& email);
+
   UserSelectionScreen* user_selection_screen() {
     return user_selection_screen_.get();
   }

chrome/browser/chromeos/login/ui/login_display_mojo.cc

@@ -137,7 +137,7 @@ void LoginDisplayMojo::ShowError(int error_msg_id,
 }
 
 void LoginDisplayMojo::ShowErrorScreen(LoginDisplay::SigninError error_id) {
-  NOTIMPLEMENTED();
+  host_->ShowErrorScreen(error_id);
 }
 
 void LoginDisplayMojo::ShowPasswordChangedDialog(bool show_password_error,
@@ -146,7 +146,7 @@ void LoginDisplayMojo::ShowPasswordChangedDialog(bool show_password_error,
 }
 
 void LoginDisplayMojo::ShowSigninUI(const std::string& email) {
-  NOTIMPLEMENTED();
+  host_->ShowSigninUI(email);
 }
 
 void LoginDisplayMojo::ShowWhitelistCheckFailedError() {