Rework approach to allowing extra flags for CrOS builds.

build/toolchain/cros/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("//build/config/compiler/compiler.gni")
 import("//build/config/sysroot.gni")
 import("//build/toolchain/gcc_toolchain.gni")
 import("//build/toolchain/cros_toolchain.gni")
 
 # This is the normal toolchain for most targets.
 gcc_toolchain("target") {
   ar = cros_target_ar
   cc = cros_target_cc
   cxx = cros_target_cxx
   ld = cxx
   if (cros_target_ld != "") {
     ld = cros_target_ld
   }
   if (cros_target_nm != "") {
     nm = cros_target_nm
   }
   if (cros_target_readelf != "") {
     readelf = cros_target_readelf
   }
-  extra_cflags = cros_target_extra_cflags
-  extra_cppflags = cros_target_extra_cppflags
-  extra_cxxflags = cros_target_extra_cxxflags
-  extra_ldflags = cros_target_extra_ldflags
 
   toolchain_args = {
     cc_wrapper = ""
     current_cpu = target_cpu
     current_os = "chromeos"
     is_clang = is_clang
     use_debug_fission = use_debug_fission
     use_gold = use_gold
     use_sysroot = use_sysroot
   }
@@ skipping 10 matching lines @@
   ld = cxx
   if (cros_target_ld != "") {
     ld = cros_target_ld
   }
   if (cros_target_nm != "") {
     nm = cros_target_nm
   }
   if (cros_target_readelf != "") {
     readelf = cros_target_readelf
   }
-  extra_cflags = cros_nacl_bootstrap_extra_cflags
-  extra_cppflags = cros_nacl_bootstrap_extra_cppflags
-  extra_cxxflags = cros_nacl_bootstrap_extra_cxxflags
-  extra_ldflags = cros_nacl_bootstrap_extra_ldflags
 
   toolchain_args = {
     cc_wrapper = ""
     current_cpu = target_cpu
     current_os = "chromeos"
     is_clang = is_clang
     use_debug_fission = false
     use_gold = false
     use_sysroot = false
   }
 }
 
 gcc_toolchain("host") {
   # These are args for the template.
   ar = cros_host_ar
   cc = cros_host_cc
   cxx = cros_host_cxx
   ld = cxx
   if (cros_host_ld != "") {
     ld = cros_host_ld
   }
   if (cros_host_nm != "") {
     nm = cros_host_nm
   }
   if (cros_host_readelf != "") {
     readelf = cros_host_readelf
   }
-  extra_cflags = cros_host_extra_cflags
-  extra_cppflags = cros_host_extra_cppflags
-  extra_cxxflags = cros_host_extra_cxxflags
-  extra_ldflags = cros_host_extra_ldflags
 
   toolchain_args = {
     cc_wrapper = ""
     is_clang = cros_host_is_clang
     current_cpu = host_cpu
     current_os = "linux"
     use_sysroot = false
   }
 }
 
 gcc_toolchain("v8_snapshot") {
   # These are args for the template.
   ar = cros_v8_snapshot_ar
   cc = cros_v8_snapshot_cc
   cxx = cros_v8_snapshot_cxx
   ld = cxx
   if (cros_v8_snapshot_ld != "") {
     ld = cros_v8_snapshot_ld
   }
   if (cros_v8_snapshot_nm != "") {
     nm = cros_v8_snapshot_nm
   }
   if (cros_v8_snapshot_readelf != "") {
     readelf = cros_v8_snapshot_readelf
   }
-  extra_cflags = cros_v8_snapshot_extra_cflags
-  extra_cppflags = cros_v8_snapshot_extra_cppflags
-  extra_cxxflags = cros_v8_snapshot_extra_cxxflags
-  extra_ldflags = cros_v8_snapshot_extra_ldflags
 
   toolchain_args = {
     cc_wrapper = ""
     is_clang = cros_v8_snapshot_is_clang
     if (target_cpu == "x86" || target_cpu == "arm" || target_cpu == "mipsel") {
       current_cpu = "x86"
     } else {
       current_cpu = "x64"
     }
     v8_current_cpu = v8_target_cpu
     current_os = "linux"
     use_sysroot = false
   }
 }