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

ios/chrome/browser/net/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("net") {
   sources = [
     "chrome_cookie_store_ios_client.h",
     "chrome_cookie_store_ios_client.mm",
     "connection_type_observer_bridge.h",
     "connection_type_observer_bridge.mm",
@@ skipping 51 matching lines @@
     "mock_image_fetcher.h",
     "mock_image_fetcher.mm",
   ]
   deps = [
     ":net",
     "//testing/gmock",
   ]
 }
 
 source_set("unit_tests") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
     "cookie_util_unittest.mm",
     "image_fetcher_unittest.mm",
     "metrics_network_client_unittest.mm",
     "retryable_url_fetcher_unittest.mm",
   ]
   deps = [
     ":net",
     "//base",
     "//base/test:test_support",
     "//ios/web:test_support",
     "//net",
     "//net:test_support",
     "//testing/gtest",
   ]
 }