Add PageLoad metrics for multi-tab loading cases

chrome/test/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/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 1331 matching lines @@
       "../browser/net/nqe/ui_network_quality_estimator_service_test_util.cc",
       "../browser/net/nqe/ui_network_quality_estimator_service_test_util.h",
       "../browser/net/nss_context_chromeos_browsertest.cc",
       "../browser/net/predictor_browsertest.cc",
       "../browser/net/proxy_browsertest.cc",
       "../browser/net/sdch_browsertest.cc",
       "../browser/net/websocket_browsertest.cc",
       "../browser/ntp_snippets/content_suggestions_service_factory_browsertest.cc",
       "../browser/page_load_metrics/observers/ads_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer_browsertest.cc",
+      "../browser/page_load_metrics/observers/multi_tab_loading_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/page_load_metrics_browsertest.cc",
       "../browser/password_manager/credential_manager_browsertest.cc",
       "../browser/password_manager/password_manager_browsertest.cc",
       "../browser/pdf/pdf_extension_test.cc",
       "../browser/pdf/pdf_extension_test_util.cc",
       "../browser/pdf/pdf_extension_test_util.h",
       "../browser/permissions/permission_request_manager_browsertest.cc",
       "../browser/permissions/permissions_browsertest.cc",
       "../browser/permissions/permissions_browsertest.h",
       "../browser/plugins/flash_permission_browsertest.cc",
@@ skipping 1795 matching lines @@
     "../browser/page_load_metrics/observers/amp_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/data_reduction_proxy_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/delay_navigation_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/google_captcha_observer_unittest.cc",
     "../browser/page_load_metrics/observers/loading_predictor_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/lofi_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/media_page_load_metrics_observer_unittest.cc",
+    "../browser/page_load_metrics/observers/multi_tab_loading_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc",
     "../browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h",
     "../browser/page_load_metrics/observers/previews_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/protocol_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/service_worker_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/subresource_filter_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/tab_restore_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/page_load_metrics_util_unittest.cc",
     "../browser/page_load_metrics/user_input_tracker_unittest.cc",
@@ skipping 1986 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }