Adds support for webrtc::test::ResourcePath on iOS

webrtc/test/test.gyp

Index: webrtc/test/test.gyp
diff --git a/webrtc/test/test.gyp b/webrtc/test/test.gyp
index ea831a1471abdbe775d4136be72472b8af3775ff..a19288eaeda32f743fe081a0607b5c54e71b259b 100644
--- a/webrtc/test/test.gyp
+++ b/webrtc/test/test.gyp
@@ -124,6 +124,7 @@
         'testsupport/frame_writer.cc',
         'testsupport/frame_writer.h',
         'testsupport/gtest_disable.h',
+        'testsupport/iosfileutils.mm',
         'testsupport/mock/mock_frame_reader.h',
         'testsupport/mock/mock_frame_writer.h',
         'testsupport/packet_reader.cc',
@@ -133,6 +134,13 @@
         'testsupport/trace_to_stderr.cc',
         'testsupport/trace_to_stderr.h',
       ],
+      'conditions': [
+        ['OS=="ios"', {
+          'xcode_settings': {
+            'CLANG_ENABLE_OBJC_ARC': 'YES',
+          },
+        }],
+      ],
     },
     {
       # Depend on this target when you want to have test_support but also the