GN: Simplify config by unconditionalising a flag that nacl-clang recognises

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 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("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
@@ skipping 917 matching lines @@
     # http://crbug.com/255186
     "-Wno-deprecated-register",
 
     # TODO(thakis): This used to be implied by -Wno-unused-function,
     # which we no longer use. Check if it makes sense to remove
     # this as well. http://crbug.com/316352
     "-Wno-unneeded-internal-declaration",
 
     # TODO(thakis): Remove, http://crbug.com/263960
     "-Wno-reserved-user-defined-literal",
+
+    # TODO(hans): Get this cleaned up.
+    "-Wno-inconsistent-missing-override",
   ]
-
-  # NaCl's Clang compiler and Chrome's hermetic Clang compiler will almost
-  # always have different versions. Certain flags may not be recognized by
-  # one version or the other.
-  if (!is_nacl) {
-    # Flags NaCl does not recognize.
-    default_warning_flags += [
-      # TODO(hans): Get this cleaned up.
-      "-Wno-inconsistent-missing-override",
-    ]
-  }
 }
 
 # chromium_code ---------------------------------------------------------------
 #
 # Toggles between higher and lower warnings for code that is (or isn't)
 # part of Chromium.
 
 config("chromium_code") {
   if (is_win) {
     cflags = [ "/W4" ]  # Warning level 4.
@@ skipping 293 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }