Disable NSS build targets in a Dartium build.

runtime/bin/net/ssl.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 src/net/third_party/nss/ssl.gyp.
 # Revision 165464 (this should agree with "nss_rev" in DEPS).
 {
   # Conditions section for ssl-bodge (Compiling SSL on linux using system
   # NSS and NSPR libraries) removed:
   # 'conditions': [
   #   [ 'os_posix == 1 and OS != "mac" and OS != "ios"', {
   #   ...
   #   }]],
 
   # Added by Dart. All Dart comments refer to the following block or line.
   'includes': [
     '../../tools/gyp/runtime-configurations.gypi',
     '../../tools/gyp/nss_configurations.gypi',
   ],
   # Added by Dart.
   'variables': {
     'ssl_directory': '../../../third_party/net_nss',
     'os_posix': 0,
   },
+  # Added by Dart.  We do not indent, so diffs with the original are clearer.
+  'conditions': [[ 'in_dartium==0', {
   'targets': [
     {
       'target_name': 'libssl_dart',
       'type': 'static_library',
       # Changed by Dart: '<(ssl_directory)/' added to all paths.
       'sources': [
         '<(ssl_directory)/ssl/authcert.c',
         '<(ssl_directory)/ssl/cmpcert.c',
         '<(ssl_directory)/ssl/derive.c',
         '<(ssl_directory)/ssl/dtls1con.c',
@@ skipping 116 matching lines @@
       ],
       'configurations': {
         'Debug_Base': {
           'defines': [
             'DEBUG',
           ],
         },
       },
     },
   ],
+  }]],
 }