Add Mojo types and service definitions for Background Sync API

content/public/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/config/features.gni")
 import("//content/common/common.gni")
 import("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
 
 # See //content/BUILD.gn for how this works.
 group("common") {
@@ skipping 33 matching lines @@
   if (!enable_plugins) {
     sources -= [
       "pepper_plugin_info.cc",
       "pepper_plugin_info.h",
     ]
   }
 }
 
 mojom("mojo_bindings") {
   sources = [
+    "background_sync.mojom",
     "mojo_geoposition.mojom",
     "permission_status.mojom",
   ]
 }