Add the download component and initial setup

chrome/browser/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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 332 matching lines @@
     "download/download_path_reservation_tracker.cc",
     "download/download_path_reservation_tracker.h",
     "download/download_prefs.cc",
     "download/download_prefs.h",
     "download/download_query.cc",
     "download/download_query.h",
     "download/download_request_limiter.cc",
     "download/download_request_limiter.h",
     "download/download_resource_throttle.cc",
     "download/download_resource_throttle.h",
+    "download/download_service_factory.cc",
+    "download/download_service_factory.h",
     "download/download_started_animation.h",
     "download/download_stats.cc",
     "download/download_stats.h",
     "download/download_status_updater.cc",
     "download/download_status_updater.h",
     "download/download_status_updater_mac.mm",
     "download/download_status_updater_win.cc",
     "download/download_target_determiner.cc",
     "download/download_target_determiner.h",
     "download/download_target_determiner_delegate.h",
@@ skipping 1109 matching lines @@
     "//components/crx_file",
     "//components/data_reduction_proxy/content/browser",
     "//components/data_reduction_proxy/core/browser",
     "//components/data_usage/core",
     "//components/data_use_measurement/content",
     "//components/data_use_measurement/core:ascriber",
     "//components/device_event_log",
     "//components/dom_distiller/content/browser",
     "//components/domain_reliability",
     "//components/doodle",
+    "//components/download",
     "//components/error_page/common",
     "//components/favicon/content",
     "//components/favicon/core",
     "//components/favicon_base",
     "//components/flags_ui",
     "//components/gcm_driver",
     "//components/google/core/browser",
     "//components/guest_view/browser",
     "//components/handoff",
     "//components/history/content/browser",
@@ skipping 3204 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_forwarder_manifest") {
   name = "preferences_forwarder"
   source = "prefs/forwarder_manifest.json"
 }