NaCl GN build: Remove some unneeded #defines

build/config/nacl/BUILD.gn

 # Copyright (c) 2014 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Native Client Definitions
 config("nacl_defines") {
   defines = [
-    "NACL_ANDROID=0",
     "_DEFAULT_SOURCE=1",
     "_BSD_SOURCE=1",
     "_POSIX_C_SOURCE=199506",
     "_XOPEN_SOURCE=600",
     "_GNU_SOURCE=1",
     "__STDC_LIMIT_MACROS=1",
   ]
-
-  if (is_win) {
-    defines += [ "NACL_WINDOWS=1" ]
-  } else {
-    defines += [ "NACL_WINDOWS=0" ]
-  }
-
-  if (is_linux) {
-    defines += [ "NACL_LINUX=1" ]
-  } else {
-    defines += [ "NACL_LINUX=0" ]
-  }
-
-  if (is_mac) {
-    defines += [ "NACL_OSX=1" ]
-  } else {
-    defines += [ "NACL_OSX=0" ]
-  }
-
-  if (current_cpu == "arm") {
-    defines += [
-      "NACL_BUILD_ARCH=arm",
-      "NACL_BUILD_SUBARCH=32",
-    ]
-  }
-
-  if (current_cpu == "mips") {
-    defines += [
-      "NACL_BUILD_ARCH=mips",
-      "NACL_BUILD_SUBARCH=32",
-    ]
-  }
-
-  if (current_cpu == "x86") {
-    defines += [
-      "NACL_BUILD_ARCH=x86",
-      "NACL_BUILD_SUBARCH=32",
-    ]
-  }
-
-  if (current_cpu == "x64") {
-    defines += [
-      "NACL_BUILD_ARCH=x86",
-      "NACL_BUILD_SUBARCH=64",
-    ]
-  }
 }
 
 config("nexe_defines") {
   defines = [
     "DYNAMIC_ANNOTATIONS_ENABLED=1",
     "DYNAMIC_ANNOTATIONS_PREFIX=NACL_",
   ]
 }
 
 # The base target that all targets in the NaCl build should depend on.
 # This allows configs to be modified for everything in the NaCl build, even when
 # the NaCl build is composed into the Chrome build.  (GN has no functionality to
 # add flags to everythin in //native_client, having a base target works around
 # that limitation.)
 source_set("nacl_base") {
   public_configs = [ ":nacl_defines" ]
   if (current_os == "nacl") {
     public_configs += [ ":nexe_defines" ]
   }
 }