Prepares for arm64 cross-build.

runtime/bin/net/nss.gyp

 # 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.
 
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. 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 a modified copy of Chromium's deps/third_party/nss/nss.gyp.
 # Revision 257452 (this should agree with "nss_rev" in DEPS).
@@ skipping 57 matching lines @@
         ],
       },
       # Added by Dart.
       'Dart_simarm64_Base': {
         'defines': [
           'NSS_X86_OR_X64',
           'NSS_X64',
           'NSS_USE_64',
         ],
       },
+      'Dart_arm64_Base': {
+        'defines': [
+          'NSS_USE_64',
+        ],
+      },
     },
     'conditions': [
       ['OS=="win"', {
         'configurations': {
           'Common_Base': {
             'msvs_configuration_attributes': {
               # Do not compile NSPR and NSS with /D _UNICODE /D UNICODE.
               'CharacterSet': '0'
             }
           }
@@ skipping 1270 matching lines @@
             '-Wno-logical-op-parentheses',
             '-Wno-switch',
             '-Wno-tautological-compare',
           ],
         }],
       ],
     },
   ],
   }]],
 }