Use an explicit identifier in Config

webrtc/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.
 
 # TODO(kjellander): Rebase this to webrtc/build/common.gypi changes after r6330.
 
@@ skipping 220 matching lines @@
     "common_types.cc",
     "common_types.h",
     "config.cc",
     "config.h",
     "engine_configurations.h",
     "typedefs.h",
   ]
 
   configs += [ ":common_config" ]
   public_configs = [ ":common_inherited_config" ]
+
+  if (is_clang) {
+    # Suppress warnings from Chrome's Clang plugins.
+    # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
+    configs -= [ "//build/config/clang:find_bad_constructs" ]

[tommi, 2016/01/13 16:11:21]

This line triggers the following error when trying to roll into Chrome:

/b/build/slave/linux/build/src/buildtools/linux64/gn gen //out/Release
'--args=ffmpeg_branding="Chrome" proprietary_codecs=true is_debug=false
is_component_build=false use_goma=true goma_dir="/b/build/goma" symbol_level=1
dcheck_always_on=true' --check
--runtime-deps-list-file=/b/build/slave/linux/build/src/out/Release/runtime_deps
  -> returned 1
ERROR at //third_party/webrtc/BUILD.gn:245:18: Item not found
    configs -= [ "//build/config/clang:find_bad_constructs" ]
                 ^-----------------------------------------
You were trying to remove "//build/config/clang:find_bad_constructs"
from the list but it wasn't there.
GN gen failed: 1
step returned non-zero exit code: 1
@@@STEP_FAILURE@@@

+  }
 }
 
 source_set("gtest_prod") {
   sources = [
     "test/testsupport/gtest_prod_util.h",
   ]
 }
 
 if (rtc_enable_protobuf) {
   proto_library("rtc_event_log_proto") {
@@ skipping 32 matching lines @@
 if (use_libfuzzer || use_drfuzz) {
   # This target is only here for gn to discover fuzzer build targets under
   # webrtc/test/fuzzers/.
   group("webrtc_fuzzers_dummy") {
     testonly = true
     deps = [
       "test/fuzzers:webrtc_fuzzer_main",
     ]
   }
 }