[ObjC ARC] Converts ios/chrome/browser/voice:unit_tests to ARC.Automatically generated ARCMigrate…

ios/chrome/browser/voice/BUILD.gn

 # Copyright 2015 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("voice") {
   sources = [
     "speech_input_locale.h",
     "speech_input_locale_config.h",
     "speech_input_locale_config.mm",
     "speech_input_locale_config_impl.h",
@@ skipping 45 matching lines @@
     "//ios/chrome/browser/browser_state",
     "//ios/public/provider/chrome/browser",
     "//ios/web",
     "//net",
     "//third_party/google_toolbox_for_mac",
     "//url",
   ]
 }
 
 source_set("unit_tests") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
 
   sources = [
     "text_to_speech_listener_unittest.mm",
     "text_to_speech_parser_unittest.mm",
   ]
 
   deps = [
     "//base",
     "//ios/web",
     "//ios/web:test_support",
     "//testing/gtest",
     "//third_party/google_toolbox_for_mac",
   ]
 
   public_deps = [
     ":tts",
   ]
 }