estade@ review feedback on r175674

ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc

Index: ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc
diff --git a/ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc b/ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc
index 77839eade8867ff354cc9385bf5c240f426d4a5f..cdb494d96e3511dcc1bc171ea9433a9f6170a603 100644
--- a/ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc
+++ b/ui/base/dialogs/gtk/select_file_dialog_impl_gtk.cc
@@ -9,6 +9,7 @@
 
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
@@ -239,14 +240,14 @@ void SelectFileDialogImplGTK::AddFilters(GtkFileChooser* chooser) {
       if (!current_extension.empty()) {
         if (!filter)
           filter = gtk_file_filter_new();
-        // |file_extension| is freed in |OnFileFilterDataDestroyed()|.
-        std::string* file_extension = new std::string("." + current_extension);
+        scoped_ptr<std::string> file_extension(
+            new std::string("." + current_extension));
+        fallback_labels.insert(std::string("*").append(*file_extension));
         gtk_file_filter_add_custom(filter,
                                    GTK_FILE_FILTER_FILENAME,
                                    &FileFilterCaseInsensitive,
-                                   reinterpret_cast<gpointer>(file_extension),
+                                   file_extension.release(),
                                    &OnFileFilterDataDestroyed);
-        fallback_labels.insert(std::string("*").append(*file_extension));
       }
     }
     // We didn't find any non-empty extensions to filter on.