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

webrtc/modules/congestion_controller/BUILD.gn

Index: webrtc/modules/congestion_controller/BUILD.gn
diff --git a/webrtc/modules/congestion_controller/BUILD.gn b/webrtc/modules/congestion_controller/BUILD.gn
index 1069d624ffefac697b6e74dea0ac63ceb359729d..84c344b7f24abdda1c5106f2a1aeed0399a2d82d 100644
--- a/webrtc/modules/congestion_controller/BUILD.gn
+++ b/webrtc/modules/congestion_controller/BUILD.gn
@@ -25,9 +25,8 @@ rtc_static_library("congestion_controller") {
   # TODO(jschuh): Bug 1348: fix this warning.
   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" ]
   }