mac: Delete more 10.5-only code

chrome/common/pref_names.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/common/pref_names.h"
 
 #include "base/basictypes.h"
 
 namespace prefs {
 
@@ skipping 2016 matching lines @@
 const char kInManagedMode[] = "managed_mode";
 
 // Counts how many more times the 'profile on a network share' warning should be
 // shown to the user before the next silence period.
 const char kNetworkProfileWarningsLeft[] = "network_profile.warnings_left";
 // Tracks the time of the last shown warning. Used to reset
 // |network_profile.warnings_left| after a silence period.
 const char kNetworkProfileLastWarningTime[] =
     "network_profile.last_warning_time";
 
-#if defined(OS_MACOSX)
-// A timestamp of when the obsolete OS infobar was last shown to a user on 10.5.
-const char kMacLeopardObsoleteInfobarLastShown[] =
-    "mac_105_obsolete_infobar_last_shown";
-#endif  // defined(OS_MACOSX)
-
 }  // namespace prefs