Add target_arch config variable to .isolate files.

build/isolate.gypi

 # Copyright (c) 2012 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.
 
 # This file is meant to be included into a target to provide a rule
 # to "build" .isolate files into a .isolated file.
 #
 # To use this, create a gyp target with the following form:
 # 'conditions': [
 #   ['test_isolation_mode != "noop"', {
@@ skipping 82 matching lines @@
         '--config-variable', 'CONFIGURATION_NAME=<(CONFIGURATION_NAME)',
         '--config-variable', 'chromeos=<(chromeos)',
         '--config-variable', 'component=<(component)',
         # TODO(kbr): move this to chrome_tests.gypi:gles2_conform_tests_run
         # once support for user-defined config variables is added.
         '--config-variable',
           'internal_gles2_conform_tests=<(internal_gles2_conform_tests)',
         '--config-variable', 'icu_use_data_file_flag=<(icu_use_data_file_flag)',
         '--config-variable', 'libpeer_target_type=<(libpeer_target_type)',
         '--config-variable', 'use_openssl=<(use_openssl)',
+        '--config-variable', 'target_arch=<(target_arch)',
       ],
       'conditions': [
         # Note: When gyp merges lists, it appends them to the old value.
         ['OS=="mac"', {
           # <(mac_product_name) can contain a space, so don't use FOO=<(FOO)
           # form.
           'action': [
             '--extra-variable', 'mac_product_name', '<(mac_product_name)',
           ],
         }],
         ["test_isolation_outdir!=''", {
           'action': [ '--isolate-server', '<(test_isolation_outdir)' ],
         }],
         ['test_isolation_fail_on_missing == 0', {
           'action': ['--ignore_broken_items'],
         }],
       ],
     },
   ],
 }