cros: Simple password view for lock. Adds test support.

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index 04c1ca663216db73bd297ad84a641462b4639db9..4b8b70849be49aa9ec59b63af928aed21c6cb7ce 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -216,6 +216,8 @@ component("ash") {
     "login/ui/lock_screen.h",
     "login/ui/lock_window.cc",
     "login/ui/lock_window.h",
+    "login/ui/login_password_view.cc",
+    "login/ui/login_password_view.h",
     "login_status.h",
     "magnifier/magnification_controller.cc",
     "magnifier/magnification_controller.h",
@@ -1172,6 +1174,9 @@ source_set("common_unittests") {
     "login/lock_screen_controller_unittest.cc",
     "login/mock_lock_screen_client.cc",
     "login/mock_lock_screen_client.h",
+    "login/ui/login_password_view_test.cc",
+    "login/ui/login_test_base.cc",
+    "login/ui/login_test_base.h",
     "metrics/desktop_task_switch_metric_recorder_unittest.cc",
     "metrics/pointer_metrics_recorder_unittest.cc",
     "metrics/task_switch_metrics_recorder_unittest.cc",
@@ -1295,6 +1300,7 @@ source_set("common_unittests") {
     "//chromeos:power_manager_proto",
     "//chromeos:test_support_without_gmock",
     "//components/prefs:test_support",
+    "//components/user_manager:test_support",
     "//device/bluetooth",
     "//services/ui/public/interfaces",
     "//testing/gmock",