Allow gaming_seat to use ozone gamepad as back-end

chrome/common/features.gni

 # Copyright 2015 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/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/features.gni")
 import("//device/vr/features/features.gni")
 import("//extensions/features/features.gni")
@@ skipping 31 matching lines @@
   # ChromeOS builds have this enabled by default.
   enable_hotwording = is_chrome_branded && is_chromeos
 
   # Enables usage of the system-provided notification center.
   enable_native_notifications =
       is_android || is_mac || (is_desktop_linux && use_dbus)
 
   enable_one_click_signin =
       is_win || is_mac || (is_linux && !is_chromeos && !is_chromecast)
 
+  # Indicates if Exo should use ozone gamepad. If this is false, exo will use
+  # /device/gamepad as backend.
+  enable_exo_ozone_gamepad = use_ozone
+
   # Set to true to bundle all the mash related mojo services into chrome.
   # Specify --mash to chrome to have chrome start the mash environment.
   enable_package_mash_services = is_chromeos
 
   enable_service_discovery = enable_mdns || is_mac
 
   # Enables use of the session service, which is enabled by default.
   # Android stores them separately on the Java side.
   enable_session_service = !is_android && !is_chromecast
 
@@ skipping 29 matching lines @@
   "enable_plugins=$enable_plugins",
   "enable_print_preview=$enable_print_preview",
   "enable_printing=$_enable_printing",
   "enable_service_discovery=$enable_service_discovery",
   "enable_webrtc=$enable_webrtc",
   "enable_vr=$enable_vr",
   "mac_views_browser=$mac_views_browser",
   "safe_browsing_mode=$safe_browsing_mode",
   "use_vulcanize=$use_vulcanize",
 ]