GN: Exclude suppressions of Chromium Clang warnings for Chromium builds.

webrtc/system_wrappers/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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 190 matching lines @@
     ]
     if (rtc_enable_data_logging) {
       sources += [
         "source/data_log_unittest.cc",
         "source/data_log_unittest_disabled.cc",
       ]
     }
 
     configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
-    if (is_clang) {
-      # Suppress warnings from Chrome's Clang plugins.
-      # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
+    if (!build_with_chromium && is_clang) {
+      # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
 
     deps = [
       ":metrics_default",
       ":system_wrappers",
       "../test:test_support_main",
       "//testing/gtest",
     ]
 
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_support" ]
 
       shard_timeout = 900
     }
   }
 }