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

chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc

Index: chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc
diff --git a/chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc b/chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc
index 10bd53c07666cc72189d659e1caed3caf19c4992..a099c476aac8f9b6cb0a7c32ce4d0b19e12b3ce3 100644
--- a/chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc
+++ b/chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc
@@ -1092,14 +1092,10 @@ void TabStripGtk::TabSelectionChanged(TabStripModel* tab_strip_model,
       GetTabAtAdjustForAnimation(*it)->SchedulePaint();
   }
 
-  ui::ListSelectionModel::SelectedIndices no_longer_selected;
-  std::insert_iterator<std::vector<int> > it2(no_longer_selected,
-                                              no_longer_selected.begin());
-  std::set_difference(old_model.selected_indices().begin(),
-                      old_model.selected_indices().end(),
-                      model_->selection_model().selected_indices().begin(),
-                      model_->selection_model().selected_indices().end(),
-                      it2);
+  ui::ListSelectionModel::SelectedIndices no_longer_selected =
+      base::STLSetDifference<ui::ListSelectionModel::SelectedIndices>(
+          old_model.selected_indices(),
+          model_->selection_model().selected_indices());
   for (std::vector<int>::iterator it = no_longer_selected.begin();
        it != no_longer_selected.end(); ++it) {
     GetTabAtAdjustForAnimation(*it)->StopMiniTabTitleAnimation();