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

chrome/browser/spellchecker/feedback_sender.cc

Index: chrome/browser/spellchecker/feedback_sender.cc
diff --git a/chrome/browser/spellchecker/feedback_sender.cc b/chrome/browser/spellchecker/feedback_sender.cc
index f8d4957c64efe9ad352c7c3baaa2033b65833572..8943667f175b0551b893541c095acb419f90402a 100644
--- a/chrome/browser/spellchecker/feedback_sender.cc
+++ b/chrome/browser/spellchecker/feedback_sender.cc
@@ -345,12 +345,9 @@ void FeedbackSender::RequestDocumentMarkers() {
   // longer alive.
   std::vector<int> known_renderers = feedback_.GetRendersWithMisspellings();
   std::sort(known_renderers.begin(), known_renderers.end());
-  std::vector<int> dead_renderers;
-  std::set_difference(known_renderers.begin(),
-                      known_renderers.end(),
-                      alive_renderers.begin(),
-                      alive_renderers.end(),
-                      std::back_inserter(dead_renderers));
+  std::vector<int> dead_renderers =
+      base::STLSetDifference<std::vector<int> >(known_renderers,
+                                                alive_renderers);
   for (std::vector<int>::const_iterator it = dead_renderers.begin();
        it != dead_renderers.end();
        ++it) {