Iplement the idle timer for Linux using libxss.

base/base_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 base_unittests{,.exe}.
 """
 
 Import('env')
 
@@ skipping 43 matching lines @@
 
           '/safeseh',
           '/dynamicbase',
           '/ignore:4199',
           '/nxcompat',
       ],
   )
 
 if env['PLATFORM'] == 'posix':
   env.Append(
+      # We need 'Xss' (X Screen Saver) in LIBS if we want idletimer_unittest
       LIBS = [
           'event',
       ],
   )
 
 # These test files work on *all* platforms; tests that don't work
 # cross-platform live below.
 input_files = [
     'at_exit_unittest.cc',
     'atomicops_unittest.cc',
@@ skipping 52 matching lines @@
     'gfx/uniscribe_unittest.cc',
     'gfx/vector_canvas_unittest.cc',
 ]
 
 if env['PLATFORM'] in ('posix', 'darwin'):
   #env.ChromeTestProgram('debug_message', ['debug_message.cc'])
 
   # Remove files that still need to be ported from the input_files list.
   # TODO(port): delete files from this list as they get ported.
   to_be_ported_files = [
+      # We have an implementation of idle_timer, but it's unclear if we want it
+      # yet, so it's commented out for now.  Leave this 'unported'.
       'idletimer_unittest.cc',
+
       'watchdog_unittest.cc',
       'gfx/native_theme_unittest.cc',
       'gfx/uniscribe_unittest.cc',
       'gfx/vector_canvas_unittest.cc',
   ]
   for remove in to_be_ported_files:
     input_files.remove(remove)
 
 if env['PLATFORM'] == 'darwin':
   # Remove files that still need to be ported from the input_files list.
@@ skipping 27 matching lines @@
 
 env.ChromeTestProgram('base_unittests', input_files)
 
 # 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.StaticObject('perftimer.cc')
 
 # Since run_all_perftests supplies a main, we cannot have it in base.lib
 env.StaticObject('run_all_perftests.cc')