Add Startup.BrowserView.FirstPaint / .CompositingEnded histograms.

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 1604 matching lines @@
       "../browser/media/wv_test_license_server_config.cc",
       "../browser/media/wv_test_license_server_config.h",
       "../browser/media_galleries/fileapi/iapps_finder_impl_win_browsertest.cc",
       "../browser/media_galleries/fileapi/media_file_validator_browsertest.cc",
       "../browser/media_galleries/media_galleries_dialog_controller_mock.cc",
       "../browser/media_galleries/media_galleries_dialog_controller_mock.h",
       "../browser/memory/tab_manager_browsertest.cc",
       "../browser/memory/tab_manager_observer_browsertest.cc",
       "../browser/metrics/metrics_memory_details_browsertest.cc",
       "../browser/metrics/metrics_service_browsertest.cc",
+      "../browser/metrics/startup_metrics_browsertest.cc",
       "../browser/metrics/tab_reactivation_tracker_browsertest.cc",
       "../browser/net/cookie_policy_browsertest.cc",
       "../browser/net/dns_probe_browsertest.cc",
       "../browser/net/errorpage_browsertest.cc",
       "../browser/net/ftp_browsertest.cc",
       "../browser/net/load_timing_browsertest.cc",
       "../browser/net/nqe/ui_network_quality_estimator_service_browsertest.cc",
       "../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",
@@ skipping 3603 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }