[Smart Lock] Add a setting to require close proximity in order for unlocking to work.

components/proximity_auth/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("proximity_auth") {
   sources = [
     "base64url.cc",
     "base64url.h",
     "bluetooth_connection.cc",
     "bluetooth_connection.h",
     "bluetooth_connection_finder.cc",
     "bluetooth_connection_finder.h",
     "bluetooth_util.cc",
     "bluetooth_util_chromeos.cc",
     "bluetooth_util.h",
     "client.cc",
     "client.h",
     "client_observer.h",
     "connection.cc",
     "connection.h",
     "connection_finder.h",
     "connection_observer.h",
     "proximity_auth_system.cc",
     "proximity_auth_system.h",
     "remote_device.h",
     "remote_status_update.cc",
     "remote_status_update.h",
     "secure_context.h",
+    "switches.cc",
+    "switches.h",
     "wire_message.cc",
     "wire_message.h",
   ]
 
   deps = [
     "//base",
     "//device/bluetooth",
     "//net",
   ]
 }
@@ skipping 20 matching lines @@
     "//testing/gtest",
   ]
 }
 
 # Note: This is a convenience target for ease of rapid iteration during
 # development. It is not executed on any try or build bots.
 test("proximity_auth_unittests") {
   sources = [ "run_all_unittests.cc" ]
   deps = [ ":unit_tests" ]
 }