GN: Tighten up test target visibility + refactorings

webrtc/api/BUILD.gn

 # Copyright (c) 2015 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_android) {
@@ skipping 212 matching lines @@
       "../base:rtc_base_approved",
     ]
     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_api_unittests") {
     testonly = true
+    if (!is_android && !is_ios) {  # Generated targets makes this check break.

[kjellander_webrtc, 2017/04/21 12:13:59]

What I mean with this is that when building rtc_unittests for Android and iOS,
there's a bunch of extra targets generated by the templates, which has names
that aren't matched by this.
Covering all those would look spammy and ugly here, so I decided it's easier to
just exclude those platforms, since the main benefit of this is to make it clear
where the test is used and to avoid accidental dependencies.

[stefan-webrtc, 2017/04/21 12:28:27]

I think it would be good to describe this in a bit more detail in the comment.

Does it mean these tests won't run on android and ios, or does it just mean that
there will be no visibility restrictions at all?

s/makes/make

[kjellander_webrtc, 2017/04/21 12:48:21]

Done.

+      visibility = [ "//webrtc:rtc_unittests" ]
+    }
     sources = [
       "ortc/mediadescription_unittest.cc",
       "ortc/sessiondescription_unittest.cc",
       "rtcerror_unittest.cc",
     ]
 
     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" ]
     }
 
     deps = [
       ":libjingle_peerconnection_api",
       ":ortc_api",
       "//webrtc/test:test_support",
     ]
   }
 }