GN: Make //webrtc/test:fileutils visible only to //webrtc/test.

BUG=webrtc:6727
NOTRY=True

Review-Url: https://codereview.webrtc.org/2754893002
Cr-Commit-Position: refs/heads/master@{#17283}

webrtc/modules/audio_coding/BUILD.gn

@@ -1159,7 +1159,6 @@ if (rtc_include_tests) {
       "../../api/audio_codecs:builtin_audio_decoder_factory",
       "../../base:rtc_base_approved",
       "../../system_wrappers:system_wrappers",
-      "../../test:fileutils",
       "../../test:test_support",
     ]
     defines = audio_coding_defines

webrtc/modules/remote_bitrate_estimator/BUILD.gn

@@ -134,7 +134,7 @@ if (rtc_include_tests) {
       ":bwe_simulator_lib",
       ":remote_bitrate_estimator",
       "../../base:rtc_base_approved",
-      "../../test:fileutils",
+      "../../test:test_support",
     ]
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).

webrtc/test/BUILD.gn

@@ -122,6 +122,7 @@ rtc_source_set("fileutils") {
     sources += [ "testsupport/iosfileutils.mm" ]
     configs += [ "//build/config/compiler:enable_arc" ]
   }
+  visibility = [ ":*" ]
 }
 
 rtc_source_set("video_test_support") {