[CleanUp] Use base::STLSetDifference in place of std::set_difference

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/extensions/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 3107 matching lines @@
       base::Bind(&ExtensionService::ManageBlacklist,
                  AsWeakPtr(),
                  blacklisted_extensions_.GetIDs()));
 }
 
 void ExtensionService::ManageBlacklist(
     const std::set<std::string>& old_blacklisted_ids,
     const std::set<std::string>& new_blacklisted_ids) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  std::set<std::string> no_longer_blacklisted;
-  std::set_difference(old_blacklisted_ids.begin(), old_blacklisted_ids.end(),
-                      new_blacklisted_ids.begin(), new_blacklisted_ids.end(),
-                      std::inserter(no_longer_blacklisted,
-                                    no_longer_blacklisted.begin()));
-  std::set<std::string> not_yet_blacklisted;
-  std::set_difference(new_blacklisted_ids.begin(), new_blacklisted_ids.end(),
-                      old_blacklisted_ids.begin(), old_blacklisted_ids.end(),
-                      std::inserter(not_yet_blacklisted,
-                                    not_yet_blacklisted.begin()));
+  std::set<std::string> no_longer_blacklisted =
+      base::STLSetDifference<std::set<std::string> >(old_blacklisted_ids,
+                                                     new_blacklisted_ids);
+  std::set<std::string> not_yet_blacklisted =
+      base::STLSetDifference<std::set<std::string> >(new_blacklisted_ids,
+                                                     old_blacklisted_ids);
 
   for (std::set<std::string>::iterator it = no_longer_blacklisted.begin();
        it != no_longer_blacklisted.end(); ++it) {
     scoped_refptr<const Extension> extension =
         blacklisted_extensions_.GetByID(*it);
     DCHECK(extension.get()) << "Extension " << *it << " no longer blacklisted, "
                             << "but it was never blacklisted.";
     if (!extension.get())
       continue;
     blacklisted_extensions_.Remove(*it);
@@ skipping 20 matching lines @@
 }
 
 void ExtensionService::AddUpdateObserver(extensions::UpdateObserver* observer) {
   update_observers_.AddObserver(observer);
 }
 
 void ExtensionService::RemoveUpdateObserver(
     extensions::UpdateObserver* observer) {
   update_observers_.RemoveObserver(observer);
 }