Convert enable_bidirectional_stream into build flag local to net.

net/net_common.gypi

 # Copyright 2015 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 target is included in both 'net' and 'net_small'.
   'type': '<(component)',
   'variables': { 'enable_wexit_time_destructors': 1, },
   'dependencies': [
     '../base/base.gyp:base',
@@ skipping 78 matching lines @@
     ['disable_file_support!=1', {
       # TODO(mmenke):  Should probably get rid of the dependency on
       # net_resources in this case (It's used in net_util, to format
       # directory listings.  Also used outside of net/).
       'sources': ['<@(net_file_support_sources)']
     }],
     ['disable_ftp_support!=1', {
       'sources': ['<@(net_ftp_support_sources)']
     }],
     ['enable_bidirectional_stream==1', {
-     'defines': [
-        'ENABLE_BIDIRECTIONAL_STREAM',
-      ],
       'sources': ['<@(net_bidirectional_stream_sources)']
     }],
     ['enable_built_in_dns==1', {
       'defines': [
         'ENABLE_BUILT_IN_DNS',
       ]
     }, { # else
       'sources!': [
         'dns/address_sorter_posix.cc',
         'dns/address_sorter_posix.h',
@@ skipping 300 matching lines @@
         ['include', '^cert/test_root_certs_nss\\.cc$'],
         ['include', '^cert/x509_util_nss_certs\\.cc$'],
         ['include', '^cert_net/nss_ocsp\\.cc$'],
         ['include', '^cert_net/nss_ocsp\\.h$'],
         ['include', '^proxy/proxy_resolver_mac\\.cc$'],
         ['include', '^proxy/proxy_server_mac\\.cc$'],
       ],
     }],
   ],
 }