GN: Tighten up test target visibility + refactorings

webrtc/p2p/BUILD.gn

 # Copyright (c) 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")
 
@@ skipping 151 matching lines @@
     ]
 
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 
   rtc_source_set("rtc_p2p_unittests") {
     testonly = true
+    if (!is_android && !is_ios) {  # Generated targets makes this check break.
+      visibility = [ "//webrtc:rtc_unittests" ]
+    }
     sources = [
       "base/asyncstuntcpsocket_unittest.cc",
       "base/dtlstransportchannel_unittest.cc",
       "base/jseptransport_unittest.cc",
       "base/p2ptransportchannel_unittest.cc",
       "base/packetlossestimator_unittest.cc",
       "base/port_unittest.cc",
       "base/portallocator_unittest.cc",
       "base/pseudotcp_unittest.cc",
       "base/relayport_unittest.cc",
@@ skipping 47 matching lines @@
 
   deps = [
     "..:webrtc_common",
     "../base:rtc_base",
   ]
 }
 
 if (rtc_include_tests) {
   rtc_source_set("libstunprober_unittests") {
     testonly = true
+    if (!is_android && !is_ios) {  # Generated targets makes this check break.
+      visibility = [ "//webrtc:rtc_unittests" ]
+    }
     sources = [
       "stunprober/stunprober_unittest.cc",
     ]
     deps = [
       ":libstunprober",
       "//testing/gmock",
       "//testing/gtest",
     ]
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
     defines = [ "GTEST_RELATIVE_PATH" ]
   }
 }