Remove a nested config reference from the GN build.

Source/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("config.gni")
 if (is_clang) {
   import("//build/config/clang/clang.gni")
 }
 
 visibility = "//third_party/WebKit/*"
@@ skipping 14 matching lines @@
 }
 
 # config -----------------------------------------------------------------------
 
 config("config") {
   include_dirs = [ ".", ".." ]
 
   cflags = []
   defines = []
 
-  configs = [ ":non_test_config" ]

[jamesr, 2014/07/18 00:28:56]

Is there no way to default non_test_config? I guess adding it explicitly isn't
too bad but the failure mode for forgetting (less warnings) is kind of
unfortunate.

-
   if (is_win) {
     cflags += [
       "/wd4305",  # Truncation from 'type1' to 'type2'.
       "/wd4324",  # Struct padded due to declspec(align).
       "/wd4714",  # Function marked forceinline not inlined.
       "/wd4800",  # Value forced to bool.
       "/wd4996",  # Deprecated function call.
     ]
   }
 
@@ skipping 26 matching lines @@
 
 # The follow configs apply to all targets except for unit tests, which rely on
 # static initializers.
 config("non_test_config") {
   cflags = []
 
   if (is_clang) {
     cflags += [ "-Wglobal-constructors" ]
   }
 }