GN: Use rtc_include_tests variable to exclude tests.

webrtc/tools/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("//testing/test.gni")
 import("../build/webrtc.gni")
@@ skipping 146 matching lines @@
   sources = [
     "agc/test_utils.cc",
     "agc/test_utils.h",
   ]
 
   configs += [ "..:common_config" ]
   public_configs = [ "..:common_inherited_config" ]
 }
 
 # Exclude tools depending on gflags since that's not available in Chromium.
-# There's no point processing WebRTC standalone tests in a Chromium build.
-if (!build_with_chromium) {
+if (!rtc_include_tests) {
   executable("agc_harness") {
     testonly = true
     sources = [
       "agc/agc_harness.cc",
     ]
 
     configs += [ "..:common_config" ]
     public_configs = [ "..:common_inherited_config" ]
 
     if (is_clang) {
@@ skipping 89 matching lines @@
       ":video_quality_analysis",
       "../test:test_support_main",
       "//testing/gtest",
     ]
 
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_support" ]
     }
   }
 }