Move Tuple to base namespace.

ui/shell_dialogs/select_file_dialog_win.cc

Index: ui/shell_dialogs/select_file_dialog_win.cc
diff --git a/ui/shell_dialogs/select_file_dialog_win.cc b/ui/shell_dialogs/select_file_dialog_win.cc
index 2ada0ce1f69b2227e35bf2b8e523101b119597c4..bf0d30b085f9d4cb792591d3ff7f69301dcf06aa 100644
--- a/ui/shell_dialogs/select_file_dialog_win.cc
+++ b/ui/shell_dialogs/select_file_dialog_win.cc
@@ -514,12 +514,12 @@ bool SelectFileDialogImpl::SaveFileAsWithFilter(
   // Figure out what filter got selected. The filter index is 1-based.
   std::wstring filter_selected;
   if (*index > 0) {
-    std::vector<Tuple<base::string16, base::string16>> filters =
+    std::vector<base::Tuple<base::string16, base::string16>> filters =
         ui::win::OpenFileName::GetFilters(save_as.GetOPENFILENAME());
     if (*index > filters.size())
       NOTREACHED() << "Invalid filter index.";
     else
-      filter_selected = get<1>(filters[*index - 1]);
+      filter_selected = base::get<1>(filters[*index - 1]);
   }
 
   // Get the extension that was suggested to the user (when the Save As dialog