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

net/net_perftests.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_perftests{,.exe} executable.
 """
 
 Import('env')
 
 env = env.Clone()
 
 env.ApplySConscript([
     '$BASE_DIR/using_base.scons',
     '$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',
 ])
 
-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',
       ],
   )
-elif env['PLATFORM'] == 'posix':
+elif env.Bit('linux'):
   env.Append(
       # TODO(port): disk_cache_perftest breaks strict aliasing rules.
       CCFLAGS = ['-fno-strict-aliasing'],
   )
 
 input_files = [
     'base/cookie_monster_perftest.cc',
     'disk_cache/disk_cache_perftest.cc',
     'disk_cache/disk_cache_test_util$OBJSUFFIX',
 
     # TODO(sgk): avoid using .cc from base directly
     '$OBJ_ROOT/base/run_all_perftests$OBJSUFFIX',
     '$OBJ_ROOT/base/perftimer$OBJSUFFIX',
 ]
 
-if env['PLATFORM'] in ('posix', 'win32'):
-
+if not env.Bit('mac'):
   env.ChromeTestProgram('net_perftests', input_files)