GN: Tighten up test target visibility + refactorings

webrtc/modules/audio_processing/BUILD.gn

 # Copyright (c) 2014 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("//build/config/arm.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 467 matching lines @@
         ":audioproc_unittest_proto",
         ":unpack_aecdump",
         "test/conversational_speech",
         "test/py_quality_assessment",
       ]
     }
   }
 
   rtc_source_set("audio_processing_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/modules:modules_unittests" ]
+    }
     sources = [
       "aec/echo_cancellation_unittest.cc",
       "aec/system_delay_unittest.cc",
       "agc/agc_manager_direct_unittest.cc",
       "agc/loudness_histogram_unittest.cc",
       "agc/mock_agc.h",
       "audio_buffer_unittest.cc",
       "beamformer/array_util_unittest.cc",
       "beamformer/complex_matrix_unittest.cc",
       "beamformer/covariance_matrix_generator_unittest.cc",
@@ skipping 146 matching lines @@
     # Dependency chain (there may also be others):
     #  //webrtc/modules/audio_processing:audio_processing_perf_tests -->
     #  //webrtc/modules:modules_unittests --[private]-->
     #  //webrtc/modules:modules_unittests_apk -->
     #  //webrtc/modules:modules_unittests_apk__create -->
     #  //webrtc/modules:modules_unittests_apk__create__finalize -->
     #  //webrtc/modules:modules_unittests_apk__create__package --[private]-->
     #  //webrtc/modules:_modules_unittests__library
     check_includes = false
     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:webrtc_perf_tests" ]
+    }
     sources = [
       "audio_processing_performance_unittest.cc",
       "level_controller/level_controller_complexity_unittest.cc",
       "residual_echo_detector_complexity_unittest.cc",
     ]
     deps = [
       ":audio_processing",
       ":audioproc_test_utils",
       "../../base:protobuf_utils",
       "//testing/gtest",
@@ skipping 159 matching lines @@
 
       deps = [
         ":audioproc_debug_proto",
         "../..:webrtc_common",
         "../../base:protobuf_utils",
         "../../base:rtc_base_approved",
       ]
     }
   }
 }