Reland of Enabling 'gn check' on //webrtc/test.

.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("//build/dotfile_settings.gni")
 
@@ skipping 16 matching lines @@
   "//webrtc/call/*",
   "//webrtc/common_video/*",
   "//webrtc/common_audio/*",
   "//webrtc/examples/*",
   "//webrtc/logging/*",
   "//webrtc/media/*",
   "//webrtc/modules/*",
   "//webrtc/ortc/*",
   "//webrtc/stats/*",
   "//webrtc/tools/*",
+  "//webrtc/test/*",
   "//webrtc/voice_engine/*",
 ]
 
 # These are the list of GN files that run exec_script. This whitelist exists
 # to force additional review for new uses of exec_script, which is strongly
 # discouraged except for gypi_to_gn calls.
 exec_script_whitelist = build_dotfile_settings.exec_script_whitelist
 
 default_args = {
   # Webrtc does not support component builds because we are not using the
   # template "component" but we rely directly on "rtc_static_library" and
   # "rtc_shared_library". This means that we cannot use the chromium default
   # value for this argument.
   # This also means that the user can override this value using --args or
   # the args.gn file but this setting will be ignored because we don't support
   # component builds.
   is_component_build = false
 }