GN: Tighten up test target visibility + refactorings

webrtc/modules/audio_processing/BUILD.gn

Index: webrtc/modules/audio_processing/BUILD.gn
diff --git a/webrtc/modules/audio_processing/BUILD.gn b/webrtc/modules/audio_processing/BUILD.gn
index 5686dc66908dced9a188cb2929b8cf2ee035667d..679109d4f5e2f9d5cb0cdc4fdc19e6c815eb044b 100644
--- a/webrtc/modules/audio_processing/BUILD.gn
+++ b/webrtc/modules/audio_processing/BUILD.gn
@@ -485,6 +485,9 @@ if (rtc_include_tests) {
 
   rtc_source_set("audio_processing_unittests") {
     testonly = true
+    if (!is_android && !is_ios) {  # Generated targets makes this check break.
+      visibility = [ "//webrtc/modules:modules_unittests" ]
+    }
     sources = [
       "aec/echo_cancellation_unittest.cc",
       "aec/system_delay_unittest.cc",
@@ -651,6 +654,9 @@ if (rtc_include_tests) {
     #  //webrtc/modules:_modules_unittests__library
     check_includes = false
     testonly = true
+    if (!is_android && !is_ios) {  # Generated targets makes this check break.
+      visibility = [ "//webrtc:webrtc_perf_tests" ]
+    }
     sources = [
       "audio_processing_performance_unittest.cc",
       "level_controller/level_controller_complexity_unittest.cc",