cros: Add enterprise user session metrics

chrome/browser/chromeos/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//extensions/features/features.gni")
 import("//media/media_options.gni")
 import("//printing/features/features.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 712 matching lines @@
     "login/enrollment/auto_enrollment_controller.h",
     "login/enrollment/enrollment_screen.cc",
     "login/enrollment/enrollment_screen.h",
     "login/enrollment/enrollment_screen_actor.h",
     "login/enrollment/enrollment_uma.cc",
     "login/enrollment/enrollment_uma.h",
     "login/enrollment/enterprise_enrollment_helper.cc",
     "login/enrollment/enterprise_enrollment_helper.h",
     "login/enrollment/enterprise_enrollment_helper_impl.cc",
     "login/enrollment/enterprise_enrollment_helper_impl.h",
+    "login/enterprise_user_session_metrics.cc",
+    "login/enterprise_user_session_metrics.h",
     "login/error_screens_histogram_helper.cc",
     "login/error_screens_histogram_helper.h",
     "login/existing_user_controller.cc",
     "login/existing_user_controller.h",
     "login/help_app_launcher.cc",
     "login/help_app_launcher.h",
     "login/helper.cc",
     "login/helper.h",
     "login/hwid_checker.cc",
     "login/hwid_checker.h",
@@ skipping 117 matching lines @@
     "login/signin/oauth2_token_fetcher.cc",
     "login/signin/oauth2_token_fetcher.h",
     "login/signin/oauth2_token_initializer.cc",
     "login/signin/oauth2_token_initializer.h",
     "login/signin/token_handle_fetcher.cc",
     "login/signin/token_handle_fetcher.h",
     "login/signin/token_handle_util.cc",
     "login/signin/token_handle_util.h",
     "login/signin_screen_controller.cc",
     "login/signin_screen_controller.h",
-    "login/signin_specifics.cc",
     "login/signin_specifics.h",
     "login/startup_utils.cc",
     "login/startup_utils.h",
     "login/supervised/supervised_user_authentication.cc",
     "login/supervised/supervised_user_authentication.h",
     "login/supervised/supervised_user_authenticator.cc",
     "login/supervised/supervised_user_authenticator.h",
     "login/supervised/supervised_user_constants.cc",
     "login/supervised/supervised_user_constants.h",
     "login/supervised/supervised_user_creation_controller.cc",
@@ skipping 887 matching lines @@
     "policy/proto/chrome_device_policy.proto",
     "policy/proto/install_attributes.proto",
   ]
 }
 
 proto_library("attestation_proto") {
   sources = [
     "attestation/attestation_key_payload.proto",
   ]
 }