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

chrome/common/common.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.
 
 Import('env')
 
 env = env.Clone()
 
 env.SConscript([
     '$BREAKPAD_DIR/using_breakpad.scons',
@@ skipping 14 matching lines @@
         '$CHROME_SRC_DIR',
     ],
 )
 
 env.Append(
     CPPPATH = [
         '$WEBKIT_DIR/build/localized_strings',
     ],
 )
 
-if env['PLATFORM'] == 'win32':
+if env.Bit('windows'):
   env.Prepend(
       CPPPATH = [
           '$CHROME_DIR/tools/build/win',
       ],
   )
 
 input_files = []
 
-if env['PLATFORM'] in ('posix', 'win32'):
+if not env.Bit('mac'):
   # TODO(port): Port to Mac.
   input_files.extend([
       'animation.cc',
       'chrome_constants.cc',
       'chrome_counters.cc',
       'chrome_paths.cc',
       'chrome_switches.cc',
       'common_glue.cc',
       'debug_flags.cc',
       'env_vars.cc',
@@ skipping 15 matching lines @@
       'slide_animation.cc',
       'sqlite_compiled_statement.cc',
       'sqlite_utils.cc',
       'task_queue.cc',
       'throb_animation.cc',
       'thumbnail_score.cc',
       'time_format.cc',
       'visitedlink_common.cc',
   ])
 
-if env['PLATFORM'] == 'win32':
+if env.Bit('windows'):
   # TODO(port): Port these.
   input_files.extend([
       'child_process.cc',
       'chrome_plugin_lib.cc',
       'chrome_plugin_util.cc',
       'chrome_process_filter.cc',
       'classfactory.cc',
       'drag_drop_types.cc',
       'gfx/chrome_canvas_win.cc',
       'gfx/emf.cc',
@@ skipping 13 matching lines @@
       'process_watcher.cc',
       'render_messages.cc',
       'resource_bundle.cc',
       'resource_dispatcher.cc',
       'security_filter_peer.cc',
       'win_safe_util.cc',
       'win_util.cc',
       'worker_thread_ticker.cc',
   ])
 
-if env['PLATFORM'] == 'win32':
+if env.Bit('windows'):
   # Windows specific files
   input_files.extend([
       'gfx/chrome_font_win.cc',
       'ipc_channel_win.cc',
   ])
-elif env['PLATFORM'] == 'posix':
+elif env.Bit('linux'):
   input_files.extend([
       'gfx/chrome_canvas_skia.cc',
       'gfx/chrome_font_skia.cc',
   ])
 
-if env['PLATFORM'] in ['posix', 'mac']:
+if env.Bit('posix'):
   input_files.extend([
       'ipc_channel_posix.cc',
   ])
 
 
-if env['PLATFORM'] in ('posix', 'win32'):
+if not env.Bit('mac'):
   # TODO(port): This should be enabled for all platforms.
   env.ChromeStaticLibrary('common', input_files)