Revert of MD Downloads: track downloads in C++, dispatch discrete JS updates

chrome/chrome_tests_unit.gypi

Index: chrome/chrome_tests_unit.gypi
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index cdfc1f724d63d93c51bb64497ff0611c41e7a056..1f6ebff8f45c42ef546a5ad5e1e6e3745a5339a3 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1093,7 +1093,6 @@
       'browser/resources/google_now/common_test_util.js',
       'browser/resources/google_now/utility.js',
       'browser/resources/google_now/utility_test_util.js',
-      'browser/resources/md_downloads/action_service.js',
       'browser/resources/print_preview/data/measurement_system.js',
       'browser/resources/print_preview/print_preview_utils.js',
       'renderer/resources/extensions/notifications_custom_bindings.js',
@@ -1104,7 +1103,6 @@
       'browser/resources/google_now/background_unittest.gtestjs',
       'browser/resources/google_now/cards_unittest.gtestjs',
       'browser/resources/google_now/utility_unittest.gtestjs',
-      'browser/resources/md_downloads/action_service_unittest.js',
       'browser/resources/print_preview/data/measurement_system_unittest.gtestjs',
       'browser/resources/print_preview/print_preview_utils_unittest.gtestjs',
       'renderer/resources/extensions/notifications_custom_bindings.gtestjs',
@@ -1581,7 +1579,6 @@
       'browser/ui/website_settings/permission_menu_model_unittest.cc',
       'browser/ui/webui/downloads_util_unittest.cc',
       'browser/ui/webui/help/version_updater_chromeos_unittest.cc',
-      'browser/ui/webui/md_downloads/downloads_list_tracker_unittest.cc',
       'browser/ui/webui/ntp/ntp_user_data_logger_unittest.cc',
       'browser/ui/webui/options/autofill_options_handler_unittest.cc',
       'browser/ui/webui/options/clear_browser_data_handler_unittest.cc',