gn: Add missing NDEBUG define in Release

build/config/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/allocator.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 
 declare_args() {
@@ skipping 192 matching lines @@
   } else if (is_linux && !is_android && cpu_arch == "x64" &&
              !disable_iterator_debugging) {
     # Enable libstdc++ debugging facilities to help catch problems early, see
     # http://crbug.com/65151 .
     # TODO(phajdan.jr): Should we enable this for all of POSIX?
     defines += [ "_GLIBCXX_DEBUG=1" ]
   }
 }
 
 config("release") {
+  defines = [
+    "NDEBUG",
+  ]
 }
 
 # Default libraries ------------------------------------------------------------
 
 # This config defines the default libraries applied to all targets.
 config("default_libs") {
   if (is_win) {
     # TODO(brettw) this list of defaults should probably be smaller, and
     # instead the targets that use the less common ones (e.g. wininet or
     # winspool) should include those explicitly.
@@ skipping 56 matching lines @@
       "CoreText.framework",
       "Foundation.framework",
       "UIKit.framework",
     ]
   } else if (is_linux) {
     libs = [
       "dl",
     ]
   }
 }