[Extensions] Make chrome://extensions use developerPrivate for packing crxs

chrome/browser/extensions/api/developer_private/entry_picker.h

Index: chrome/browser/extensions/api/developer_private/entry_picker.h
diff --git a/chrome/browser/extensions/api/developer_private/entry_picker.h b/chrome/browser/extensions/api/developer_private/entry_picker.h
index 5fafbc6407af774c5436012554d82cfb5571a21c..da4421c89fc4000972963cc4219334ddfde29d97 100644
--- a/chrome/browser/extensions/api/developer_private/entry_picker.h
+++ b/chrome/browser/extensions/api/developer_private/entry_picker.h
@@ -42,12 +42,13 @@ class EntryPicker : public ui::SelectFileDialog::Listener {
   ~EntryPicker() override;
 
  private:
-  // ui::SelectFileDialog::Listener implementation.
+  // ui::SelectFileDialog::Listener:
   void FileSelected(const base::FilePath& path,
                     int index,
                     void* params) override;
-
   void FileSelectionCanceled(void* params) override;
+  void MultiFilesSelected(const std::vector<base::FilePath>& files,
+                          void* params) override;
 
   scoped_refptr<ui::SelectFileDialog> select_file_dialog_;
   EntryPickerClient* client_;