Convert from using env['PLATFORM'] directly to using the more flexible...

net/net_unittests.scons

 # Copyright (c) 2006-2008 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.
 
 __doc__ = """
 Configuration for building the net_unittests{,.exe} executable.
 """
 
 Import('env')
 
 env = env.Clone()
 
 env.ApplySConscript([
     '$BASE_DIR/using_base.scons',
     '$BZIP2_DIR/using_bzip2.scons',
     '$CHROME_SRC_DIR/build/using_googleurl.scons',
     '$GTEST_DIR/../using_gtest.scons',
     '$ICU38_DIR/using_icu38.scons',
     '$MODP_B64_DIR/using_modp_b64.scons',
     '$NET_DIR/using_net.scons',
     '$SDCH_DIR/using_sdch.scons',
     '$ZLIB_DIR/using_zlib.scons',
 ])
 
-if env['PLATFORM'] in ('posix', 'darwin'):
+if env.Bit('posix'):
   env.SConscript([
       '$LIBEVENT_DIR/using_libevent.scons',
   ], {'env':env})
 
-if env['PLATFORM'] == 'win32':
+if env.Bit('windows'):
   env.Prepend(
       CCFLAGS = [
           '/WX',
       ],
   )
 
 input_files = [
     'base/auth_cache_unittest.cc',
     'base/base64_unittest.cc',
     'base/bzip2_filter_unittest.cc',
@@ skipping 37 matching lines @@
     'http/http_network_transaction_unittest.cc',
     'http/http_response_headers_unittest.cc',
     'http/http_transaction_unittest.cc',
     'http/http_util_unittest.cc',
     'http/http_vary_data_unittest.cc',
     'proxy/proxy_script_fetcher_unittest.cc',
     'proxy/proxy_service_unittest.cc',
     'url_request/url_request_unittest.cc',
 ]
 
-if env['PLATFORM'] == 'win32':
+if env.Bit('windows'):
   input_files.extend([
       'base/wininet_util_unittest.cc',
       'http/http_transaction_winhttp_unittest.cc',
       'http/winhttp_request_throttle_unittest.cc',
   ])
 
-if env['PLATFORM'] == 'posix':
+if env.Bit('linux'):
   # TODO(port):
   to_be_ported_files = [
       'base/x509_certificate_unittest.cc',
       'base/sdch_filter_unittest.cc',
       'base/ssl_config_service_unittest.cc',
   ]
   input_files = list(set(input_files) - set(to_be_ported_files))
 
-if env['PLATFORM'] == 'darwin':
+if env.Bit('mac'):
   input_files.extend([
       '../base/platform_test_mac$OBJSUFFIX',
   ])
 
   # TODO(port):
   to_be_ported_files = [
       'base/x509_certificate_unittest.cc',
       'base/sdch_filter_unittest.cc',
       'base/ssl_config_service_unittest.cc',
       'url_request/url_request_unittest.cc',
   ]
   input_files = list(set(input_files) - set(to_be_ported_files))
 
 env.ChromeTestProgram('net_unittests', input_files)