Introduce lock screen app manager

chrome/browser/chromeos/BUILD.gn

Index: chrome/browser/chromeos/BUILD.gn
diff --git a/chrome/browser/chromeos/BUILD.gn b/chrome/browser/chromeos/BUILD.gn
index 6038f743d2c65f3e5c349ba539d696cd9d4be2be..75d486aea1970398de61b36857968c809be1c2fa 100644
--- a/chrome/browser/chromeos/BUILD.gn
+++ b/chrome/browser/chromeos/BUILD.gn
@@ -708,6 +708,9 @@ source_set("chromeos") {
     "launcher_search_provider/launcher_search_provider_service_factory.h",
     "locale_change_guard.cc",
     "locale_change_guard.h",
+    "lock_screen_apps/app_manager.h",
+    "lock_screen_apps/app_manager_impl.cc",
+    "lock_screen_apps/app_manager_impl.h",
     "lock_screen_apps/state_controller.cc",
     "lock_screen_apps/state_controller.h",
     "lock_screen_apps/state_observer.h",
@@ -1677,6 +1680,7 @@ source_set("unit_tests") {
     "input_method/input_method_persistence_unittest.cc",
     "input_method/input_method_util_unittest.cc",
     "locale_change_guard_unittest.cc",
+    "lock_screen_apps/app_manager_impl_unittest.cc",
     "lock_screen_apps/state_controller_unittest.cc",
     "login/auth/cryptohome_authenticator_unittest.cc",
     "login/easy_unlock/easy_unlock_challenge_wrapper_unittest.cc",