Refactor kiosk app launch to be part of login screen UI flow.

chrome/browser/chromeos/login/login_display.h

Index: chrome/browser/chromeos/login/login_display.h
diff --git a/chrome/browser/chromeos/login/login_display.h b/chrome/browser/chromeos/login/login_display.h
index 12db78d8030d3a50e5524910e3436037ef0d145c..763a66ebb9cd68da9ed41f2dd2c14057b359ec64 100644
--- a/chrome/browser/chromeos/login/login_display.h
+++ b/chrome/browser/chromeos/login/login_display.h
@@ -64,6 +64,9 @@ class LoginDisplay : public RemoveUserDelegate {
     // Sign in into the public account identified by |username|.
     virtual void LoginAsPublicAccount(const std::string& username) = 0;
 
+    // Login to kiosk mode for app with |app_id|.
+    virtual void LoginAsKioskApp(const std::string& app_id) = 0;
+
     // Notify the delegate when the sign-in UI is finished loading.
     virtual void OnSigninScreenReady() = 0;