Allow SessionService to be disabled.

chrome/browser/browsing_data_remover.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/browser/browsing_data_remover.h"
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 222 matching lines @@
     if (remove_origin_.is_empty()) {
       // We also delete the list of recently closed tabs. Since these expire,
       // they can't be more than a day old, so we can simply clear them all.
       TabRestoreService* tab_service =
           TabRestoreServiceFactory::GetForProfile(profile_);
       if (tab_service) {
         tab_service->ClearEntries();
         tab_service->DeleteLastSession();
       }
 
+#if defined(ENABLE_SESSION_SERVICE)
       // We also delete the last session when we delete the history.
       SessionService* session_service =
           SessionServiceFactory::GetForProfile(profile_);
       if (session_service)
         session_service->DeleteLastSession();
+#endif
     }
   }
 
   if (remove_mask & REMOVE_DOWNLOADS) {
     content::RecordAction(UserMetricsAction("ClearBrowsingData_Downloads"));
     DownloadManager* download_manager =
         DownloadServiceFactory::GetForProfile(profile_)->GetDownloadManager();
     download_manager->RemoveDownloadsBetween(delete_begin_, delete_end_);
     download_manager->ClearLastDownloadPath();
   }
@@ skipping 448 matching lines @@
       BrowserThread::UI, FROM_HERE,
       base::Bind(&BrowsingDataRemover::OnClearedServerBoundCerts,
                  base::Unretained(this)));
 }
 
 void BrowsingDataRemover::OnClearedServerBoundCerts() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   waiting_for_clear_server_bound_certs_ = false;
   NotifyAndDeleteIfDone();
 }