components: add wifi_sync component

components/wifi_sync/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.
 
 source_set("wifi_sync") {
   sources = [
+    "wifi_credential_syncable_service.cc",
+    "wifi_credential_syncable_service.h",
+    "wifi_credential_syncable_service_factory.cc",
+    "wifi_credential_syncable_service_factory.h",
     "wifi_security_class.h",
   ]
 
   deps = [
     "//base",
+    "//sync",
   ]
 
   if (is_chromeos) {
     sources += [ "wifi_security_class_chromeos.cc" ]
   }
 }
 
 source_set("unit_tests") {
   testonly = true
 
   if (is_chromeos) {
     deps = [
       ":wifi_sync",
       "//testing/gtest",
     ]
     sources = [
       "wifi_security_class_chromeos_unittest.cc"
     ]
   }
 }