Use libevent, second try. Changes this time:...

base/SConscript

 # 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_tests = env.Clone()
 
 env.Prepend(
@@ skipping 141 matching lines @@
       'sys_string_conversions_mac.cc',
       'worker_pool_mac.mm',
   ])
 
 if env['PLATFORM'] == 'posix':
   input_files.extend([
       'atomicops_internals_x86_gcc.cc',
       'base_paths_linux.cc',
       'file_util_linux.cc',
       'hmac_nss.cc',
+      'message_pump_libevent.cc',
       'nss_init.cc',
       'sys_string_conversions_linux.cc',
       'worker_pool.cc',
   ])
 
 env.ChromeStaticLibrary('base', input_files)
 
 
 env_tests.Prepend(
     CPPPATH = [
@@ skipping 11 matching lines @@
     CPPDEFINES = [
         'UNIT_TEST',
         'PNG_USER_CONFIG',
         'CHROME_PNG_WRITE_SUPPORT',
         'U_STATIC_IMPLEMENTATION',
         'GOOGLE_CHROME_BUILD',
     ],
     LIBS = [
         'base',
         'base_gfx',
+        'event',
         'gtest',
         'icuuc',
         'libpng',
         'skia',
         'zlib',
     ]
 )
 
 env_tests.Append(
     CPPPATH = [
@@ skipping 130 matching lines @@
 env.Alias('base', ['.', installed_base_unittests, icudata])
 
 # TODO(sgk) should this be moved into base.lib like everything else?  This will
 # require updating a bunch of other SConscripts which link directly against
 # this generated object file.
 env_tests.StaticObject('perftimer.cc')
 
 # Since run_all_perftests supplies a main, we cannot have it in base.lib
 env_tests.StaticObject('run_all_perftests.cc')