GN: Fix some build errors for iOS.

webrtc/test/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # TODO(kjellander): Convert the rest of the test.gyp targets and put here.
 
@@ skipping 41 matching lines @@
 source_set("test_support") {
   testonly = true
 
   sources = [
     "testsupport/fileutils.cc",
     "testsupport/fileutils.h",
     "testsupport/frame_reader.cc",
     "testsupport/frame_reader.h",
     "testsupport/frame_writer.cc",
     "testsupport/frame_writer.h",
+    "testsupport/iosfileutils.mm",
     "testsupport/mock/mock_frame_reader.h",
     "testsupport/mock/mock_frame_writer.h",
     "testsupport/packet_reader.cc",
     "testsupport/packet_reader.h",
     "testsupport/perf_test.cc",
     "testsupport/perf_test.h",
     "testsupport/trace_to_stderr.cc",
     "testsupport/trace_to_stderr.h",
   ]
 
   deps = [
     "../base:gtest_prod",
     "../system_wrappers",
     "//testing/gmock",
     "//testing/gtest",
   ]
 
+  if (is_ios) {
+    cflags = [ "-fobjc-arc" ]  # CLANG_ENABLE_OBJC_ARC = YES.
+  }
+
   if (is_android) {
     deps += [ "//base:base" ]
   }
 
   configs += [ "..:common_config" ]
   public_configs = [ "..:common_inherited_config" ]
 }
 
 source_set("test_support_main") {
   testonly = true
 
   sources = [
     "run_all_unittests.cc",
     "test_suite.cc",
     "test_suite.h",
   ]
 
   deps = [
     ":field_trial",
     ":histogram",
     ":test_support",
     "//testing/gmock",
     "//testing/gtest",
     "//third_party/gflags",
   ]
 
   configs += [ "..:common_config" ]
   public_configs = [ "..:common_inherited_config" ]
 }