iOS: Add resource files for tests and implement OutputPath

webrtc/common_video/common_video_unittests.gyp

Index: webrtc/common_video/common_video_unittests.gyp
diff --git a/webrtc/common_video/common_video_unittests.gyp b/webrtc/common_video/common_video_unittests.gyp
index b5e892caf0a0e81c866a6a3c22893dd0a4da1e19..20203f1c9c884e95dd9333b293831f7d50d94f89 100644
--- a/webrtc/common_video/common_video_unittests.gyp
+++ b/webrtc/common_video/common_video_unittests.gyp
@@ -35,6 +35,11 @@
             '<(DEPTH)/testing/android/native_test.gyp:native_test_native_code',
           ],
         }],
+        ['OS=="ios"', {
+          'mac_bundle_resources': [
+            '<(DEPTH)/resources/foreman_cif.yuv',
+          ],
+        }],
       ],
     },
   ],  # targets