GN: Tighten up test target visibility + refactorings

webrtc/sdk/BUILD.gn

 # Copyright 2016 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.
 
 import("../webrtc.gni")
 if (is_ios) {
@@ skipping 242 matching lines @@
       deps += [ "$rtc_libyuv_dir" ]
       public_deps = [
         "$rtc_libyuv_dir",
       ]
     }
   }
 
   if (rtc_include_tests) {
     rtc_source_set("rtc_sdk_peerconnection_objc_unittests") {
       testonly = true
+      if (!is_android && !is_ios) {  # Generated targets makes this check break.
+        visibility = [ "//webrtc:rtc_unittests" ]
+      }
       sources = [
         "objc/Framework/UnitTests/RTCConfigurationTest.mm",
         "objc/Framework/UnitTests/RTCDataChannelConfigurationTest.mm",
         "objc/Framework/UnitTests/RTCIceCandidateTest.mm",
         "objc/Framework/UnitTests/RTCIceServerTest.mm",
         "objc/Framework/UnitTests/RTCMediaConstraintsTest.mm",
         "objc/Framework/UnitTests/RTCPeerConnectionTest.mm",
         "objc/Framework/UnitTests/RTCSessionDescriptionTest.mm",
         "objc/Framework/UnitTests/avformatmappertests.mm",
       ]
@@ skipping 158 matching lines @@
       deps += [ "$rtc_libyuv_dir" ]
       public_deps = [
         "$rtc_libyuv_dir",
       ]
     } else {
       # Need to add a directory normally exported by libyuv.
       include_dirs = [ "$rtc_libyuv_dir/include" ]
     }
   }
 }