Avoid importing nacl config for non-NaCl toolchains.

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")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
-import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
 import("//build_overrides/build.gni")
 
 if (current_cpu == "arm" || current_cpu == "arm64") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
   import("//build/config/mips.gni")
 }
 if (is_mac) {
   import("//build/config/mac/symbols.gni")
 }
 if (is_ios) {
   import("//build/config/ios/ios_sdk.gni")
 }
+if (is_nacl) {
+  # To keep NaCl variables out of builds that don't include NaCl, all
+  # variables defined in nacl/config.gni referenced here should be protected by
+  # is_nacl conditions.
+  import("//build/config/nacl/config.gni")
+}
 
 declare_args() {
   # Default to warnings as errors for default workflow, where we catch
   # warnings with known toolchains. Allow overriding this e.g. for Chromium
   # builds on Linux that could use a different version of the compiler.
   # With GCC, warnings in no-Chromium code are always not treated as errors.
   treat_warnings_as_errors = true
 
   # Normally, Android builds are lightly optimized, even for debug builds, to
   # keep binary size down. Setting this flag to true disables such optimization
@@ skipping 1451 matching lines @@
   } else {
     cflags = [ "-O0" ]
     ldflags = []
   }
 }
 
 # Turns up the optimization level. On Windows, this implies whole program
 # optimization and link-time code generation which is very expensive and should
 # be used sparingly.
 config("optimize_max") {
-  if (is_nacl_irt) {
+  if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
     #   if (!is_debug) {
     #     configs -= [ "//build/config/compiler:default_optimization" ]
     #     configs += [ "//build/config/compiler:optimize_max" ]
     #   }
     # So this config has to have the selection logic just like
     # "default_optimization", below.
     configs = [ "//build/config/nacl:irt_optimize" ]
   } else {
@@ skipping 26 matching lines @@
 }
 
 # This config can be used to override the default settings for per-component
 # and whole-program optimization, optimizing the particular target for speed
 # instead of code size. This config is exactly the same as "optimize_max"
 # except that we use -O3 instead of -O2 on non-win, non-IRT platforms.
 #
 # TODO(crbug.com/621335) - rework how all of these configs are related
 # so that we don't need this disclaimer.
 config("optimize_speed") {
-  if (is_nacl_irt) {
+  if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
     #   if (!is_debug) {
     #     configs -= [ "//build/config/compiler:default_optimization" ]
     #     configs += [ "//build/config/compiler:optimize_max" ]
     #   }
     # So this config has to have the selection logic just like
     # "default_optimization", below.
     configs = [ "//build/config/nacl:irt_optimize" ]
   } else {
@@ skipping 25 matching lines @@
 
 config("optimize_fuzzing") {
   cflags = [ "-O1" ] + common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   visibility = [ ":default_optimization" ]
 }
 
 # The default optimization applied to all targets. This will be equivalent to
 # either "optimize" or "no_optimize", depending on the build flags.
 config("default_optimization") {
-  if (is_nacl_irt) {
+  if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # It gets optimized the same way regardless of the type of build.
     configs = [ "//build/config/nacl:irt_optimize" ]
   } else if (is_debug) {
     configs = [ ":no_optimize" ]
   } else if (optimize_for_fuzzing) {
     assert(!is_win, "Fuzzing optimize level not supported on Windows")
     configs = [ ":optimize_fuzzing" ]
   } else {
     configs = [ ":optimize" ]
@@ skipping 144 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }