Add initial support for native Linux desktop notifications

chrome/common/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/buildflag_header.gni")
 import("//build/util/process_version.gni")
 import("//chrome/common/features.gni")
 import("//chrome/process_version_rc_template.gni")  # For branding_file_path.
 import("//extensions/features/features.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
@@ skipping 19 matching lines @@
 buildflag_header("features") {
   header = "features.h"
   flags = [
     "ENABLE_APP_LIST=$enable_app_list",
     "ENABLE_BACKGROUND=$enable_background",
     "ENABLE_BASIC_PRINT_DIALOG=$enable_basic_print_dialog",
     "ENABLE_CAPTIVE_PORTAL_DETECTION=$enable_captive_portal_detection",
     "ENABLE_GOOGLE_NOW=$enable_google_now",
     "ENABLE_HANGOUT_SERVICES_EXTENSION=$enable_hangout_services_extension",
     "ENABLE_ONE_CLICK_SIGNIN=$enable_one_click_signin",
+    "ENABLE_NATIVE_NOTIFICATIONS=$enable_native_notifications",
     "ENABLE_PACKAGE_MASH_SERVICES=$enable_package_mash_services",
     "ENABLE_SERVICE_DISCOVERY=$enable_service_discovery",
     "ENABLE_SESSION_SERVICE=$enable_session_service",
     "ENABLE_SUPERVISED_USERS=$enable_supervised_users",
     "ENABLE_WAYLAND_SERVER=$enable_wayland_server",
     "ENABLE_XPC_NOTIFICATIONS=$enable_xpc_notifications",
     "PGO_BUILD=$pgo_build",
     "USE_VULCANIZE=$use_vulcanize",
   ]
 }
@@ skipping 681 matching lines @@
 mojom("instant_mojom") {
   sources = [
     "instant.mojom",
   ]
 
   public_deps = [
     "//mojo/common:common_custom_types",
     "//url/mojo:url_mojom_gurl",
   ]
 }