GN: Tighten up test target visibility + refactorings

webrtc/p2p/BUILD.gn

Index: webrtc/p2p/BUILD.gn
diff --git a/webrtc/p2p/BUILD.gn b/webrtc/p2p/BUILD.gn
index e4770cc46267b7702a2dfce8482b87bf2ecd2536..f7d59058ba500695f22d4d3317295d68771df8d5 100644
--- a/webrtc/p2p/BUILD.gn
+++ b/webrtc/p2p/BUILD.gn
@@ -165,6 +165,13 @@ if (rtc_include_tests) {
 
   rtc_source_set("rtc_p2p_unittests") {
     testonly = true
+
+    # Skip restricting visibility on mobile platforms since the tests on those
+    # gets additional generated targets which would require many lines here to
+    # cover (which would be confusing to read and hard to maintain).
+    if (!is_android && !is_ios) {
+      visibility = [ "//webrtc:rtc_unittests" ]
+    }
     sources = [
       "base/asyncstuntcpsocket_unittest.cc",
       "base/dtlstransportchannel_unittest.cc",
@@ -238,6 +245,13 @@ rtc_static_library("libstunprober") {
 if (rtc_include_tests) {
   rtc_source_set("libstunprober_unittests") {
     testonly = true
+
+    # Skip restricting visibility on mobile platforms since the tests on those
+    # gets additional generated targets which would require many lines here to
+    # cover (which would be confusing to read and hard to maintain).
+    if (!is_android && !is_ios) {
+      visibility = [ "//webrtc:rtc_unittests" ]
+    }
     sources = [
       "stunprober/stunprober_unittest.cc",
     ]