Un-nest configs in GN files.

third_party/brotli/BUILD.gn

Index: third_party/brotli/BUILD.gn
diff --git a/third_party/brotli/BUILD.gn b/third_party/brotli/BUILD.gn
index 2975f036df401585fe627b329471ad62c7bc65e9..f18c8020f135aa91e0a9219d36256585397267d4 100644
--- a/third_party/brotli/BUILD.gn
+++ b/third_party/brotli/BUILD.gn
@@ -2,6 +2,15 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+config("brotli_warnings") {
+  if (is_clang) {
+    # IncrementalCopyFastPath in decode.c can be unused.
+    # (The file looks very different upstream, this is probably no longer
+    # needed after rolling brotli the next time.)
+    cflags = [ "-Wno-unused-function" ]
+  }
+}
+
 source_set("brotli") {
   sources = [
     "dec/bit_reader.c",
@@ -23,17 +32,11 @@ source_set("brotli") {
     "dec/types.h",
   ]
 
-  config("brotli_warnings") {
-    if (is_clang) {
-      # IncrementalCopyFastPath in decode.c can be unused.
-      # (The file looks very different upstream, this is probably no longer
-      # needed after rolling brotli the next time.)
-      cflags = [ "-Wno-unused-function" ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":brotli_warnings" ]
+  configs += [
+   ":brotli_warnings",
+    "//build/config/compiler:no_chromium_code",
+  ]
 
   # Since we are never debug brotli, freeze the optimizations to -O2.
   if (is_debug) {