Implement basic ShowItemInFolder for linux....

chrome/chrome.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/common.gypi',
@@ skipping 213 matching lines @@
         'common/notification_service.cc',
         'common/notification_service.h',
         'common/notification_source.h',
         'common/notification_type.h',
         'common/os_exchange_data.cc',
         'common/os_exchange_data.h',
         'common/owned_widget_gtk.cc',
         'common/owned_widget_gtk.h',
         'common/page_transition_types.h',
         'common/page_zoom.h',
+        'common/platform_util.h',
+        'common/platform_util_linux.cc',
+        'common/platform_util_mac.mm',
+        'common/platform_util_win.cc',
         'common/plugin_messages.h',
         'common/plugin_messages_internal.h',
         'common/pref_member.cc',
         'common/pref_member.h',
         'common/pref_names.cc',
         'common/pref_names.h',
         'common/pref_service.cc',
         'common/pref_service.h',
         'common/process_watcher.cc',
         'common/process_watcher.h',
@@ skipping 2456 matching lines @@
             'Debug': {
               'msvs_precompiled_header': 'tools/build/win/precompiled.h',
               'msvs_precompiled_source': 'tools/build/win/precompiled.cc',
             },
           },
         },
       ]},  # 'targets'
     ],  # OS=="win"
   ],  # 'conditions'
 }