enabling `gn check` on the whole WebRTC repo

.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")
 
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
 # The secondary source root is a parallel directory tree where
 # GN build files are placed when they can not be placed directly
 # in the source tree, e.g. for third party source trees.
 secondary_source = "//build/secondary/"
 
 # These are the targets to check headers for by default. The files in targets
 # matching these patterns (see "gn help label_pattern" for format) will have
 # their includes checked for proper dependencies when you run either
 # "gn check" or "gn gen --check".
-# TODO(kjellander): Keep adding paths to this list as work in webrtc:5589 is done.
-check_targets = [
-  "//webrtc/api/*",
-  "//webrtc/audio/*",
-  "//webrtc/base/*",
-  "//webrtc/call/*",
-  "//webrtc/common_video/*",
-  "//webrtc/common_audio/*",
-  "//webrtc/examples/*",
-  "//webrtc/logging/*",
-  "//webrtc/media/*",
-  "//webrtc/modules/*",
-  "//webrtc/ortc/*",
-  "//webrtc/p2p/*",
-  "//webrtc/sdk/*",
-  "//webrtc/stats/*",
-  "//webrtc/system_wrappers/*",
-  "//webrtc/test/*",
-  "//webrtc/tools/*",
-  "//webrtc/video/*",
-  "//webrtc/voice_engine/*",
-]
+check_targets = [ "//webrtc/*" ]
 
 # 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
 }