Build NaCl browser tests with GN

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.
 
 import("//build/config/nacl/config.gni")
 
 # Native Client Definitions
 config("nacl_defines") {
   if (is_linux || is_android || is_nacl) {
     defines = [
       "_POSIX_C_SOURCE=199506",
       "_XOPEN_SOURCE=600",
       "_GNU_SOURCE=1",
       "__STDC_LIMIT_MACROS=1",
     ]
   } else if (is_win) {
     defines = [ "__STDC_LIMIT_MACROS=1" ]
   }
+
+  if (current_cpu == "pnacl" && !is_nacl_nonsfi) {
+    # TODO: Remove the following definition once NACL_BUILD_ARCH and
+    # NACL_BUILD_SUBARCH are defined by the PNaCl toolchain.
+    defines += [ "NACL_BUILD_ARCH=pnacl" ]
+  }
 }
 
 config("nexe_defines") {
   defines = [
     "DYNAMIC_ANNOTATIONS_ENABLED=1",
     "DYNAMIC_ANNOTATIONS_PREFIX=NACL_",
   ]
 }
 
 config("nacl_warnings") {
@@ skipping 99 matching lines @@
     "-Os",
 
     # These are omitted from non-IRT libraries to keep the libraries
     # themselves small.
     "-ffunction-sections",
     "-fdata-sections",
   ]
 
   ldflags = [ "-Wl,--gc-sections" ]
 }