Start adding TLS (SSL) sockets to dart:io.

runtime/bin/bin.gypi

 # 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.
 
 {
   'variables': {
     'crypto_cc_file': '<(SHARED_INTERMEDIATE_DIR)/crypto_gen.cc',
     'io_cc_file': '<(SHARED_INTERMEDIATE_DIR)/io_gen.cc',
     'json_cc_file': '<(SHARED_INTERMEDIATE_DIR)/json_gen.cc',
     'uri_cc_file': '<(SHARED_INTERMEDIATE_DIR)/uri_gen.cc',
@@ skipping 276 matching lines @@
               'msvs_configuration_attributes': {
                 'CharacterSet': '0',
               },
             },
           },
         }],
         ['OS=="linux"', {
           'link_settings': {
             'libraries': [
               '-ldl',
+              '-lssl',
             ],
           },
         }],
       ],
     },
     {
       'target_name': 'libdart_withcore',
       'type': 'static_library',
       'dependencies': [
         'libdart_lib_withcore',
@@ skipping 218 matching lines @@
         ['OS=="mac"', {
           'xcode_settings': {
             'OTHER_LDFLAGS': [ '-undefined', 'dynamic_lookup' ],
           },
         }],
       ],
     },
   ],
 }