[ObjC ARC] Converts ios/chrome/browser/autofill:eg_tests to ARC.

ios/chrome/browser/autofill/BUILD.gn

 # Copyright 2016 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("autofill") {
   sources = [
     "form_input_accessory_view.h",
     "form_input_accessory_view.mm",
     "form_input_accessory_view_controller.h",
     "form_input_accessory_view_controller.mm",
@@ skipping 92 matching lines @@
     "//ios/chrome/test/base",
     "//ios/web",
     "//ios/web:test_support",
     "//testing/gtest",
     "//third_party/ocmock",
     "//ui/base:test_support",
   ]
 }
 
 source_set("eg_tests") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
     "form_input_egtest.mm",
   ]
   deps = [
     ":autofill",
     "//base",
     "//base/test:test_support",
     "//ios/chrome/app/strings",
     "//ios/chrome/browser/ui",
     "//ios/chrome/test/app:test_support",
     "//ios/chrome/test/earl_grey:test_support",
     "//ios/testing:ios_test_support",
     "//ios/testing/earl_grey:earl_grey_support",
     "//ios/third_party/earl_grey",
     "//ios/web:earl_grey_test_support",
     "//ios/web:test_support",
   ]
 }