Prioritize ARC instance only when it is needed

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 211 matching lines @@
     "arc/arc_session_manager.h",
     "arc/arc_support_host.cc",
     "arc/arc_support_host.h",
     "arc/auth/arc_auth_code_fetcher.h",
     "arc/auth/arc_background_auth_code_fetcher.cc",
     "arc/auth/arc_background_auth_code_fetcher.h",
     "arc/auth/arc_manual_auth_code_fetcher.cc",
     "arc/auth/arc_manual_auth_code_fetcher.h",
     "arc/auth/arc_robot_auth_code_fetcher.cc",
     "arc/auth/arc_robot_auth_code_fetcher.h",
+    "arc/boot_phase_monitor/arc_boot_phase_monitor_bridge.cc",
+    "arc/boot_phase_monitor/arc_boot_phase_monitor_bridge.h",
+    "arc/boot_phase_monitor/arc_instance_throttle.cc",
+    "arc/boot_phase_monitor/arc_instance_throttle.h",
     "arc/downloads_watcher/arc_downloads_watcher_service.cc",
     "arc/downloads_watcher/arc_downloads_watcher_service.h",
     "arc/enterprise/arc_enterprise_reporting_service.cc",
     "arc/enterprise/arc_enterprise_reporting_service.h",
     "arc/extensions/arc_support_message_host.cc",
     "arc/extensions/arc_support_message_host.h",
     "arc/fileapi/arc_content_file_system_async_file_util.cc",
     "arc/fileapi/arc_content_file_system_async_file_util.h",
     "arc/fileapi/arc_content_file_system_backend_delegate.cc",
     "arc/fileapi/arc_content_file_system_backend_delegate.h",
@@ skipping 1464 matching lines @@
     "policy/proto/chrome_device_policy.proto",
     "policy/proto/install_attributes.proto",
   ]
 }
 
 proto_library("attestation_proto") {
   sources = [
     "attestation/attestation_key_payload.proto",
   ]
 }