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

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/developer_private/entry_picker.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/extensions/api/developer_private/developer_private_api.h"
@@ skipping 61 matching lines @@
                                void* params) {
   client_->FileSelected(path);
   delete this;
 }
 
 void EntryPicker::FileSelectionCanceled(void* params) {
   client_->FileSelectionCanceled();
   delete this;
 }
 
+void EntryPicker::MultiFilesSelected(const std::vector<base::FilePath>& files,
+                                     void* params) {
+  NOTREACHED();
+  client_->FileSelectionCanceled();
+  delete this;
+}
+
 // static
 void EntryPicker::SkipPickerAndAlwaysSelectPathForTest(
     base::FilePath* path) {
   g_skip_picker_for_test = true;
   g_path_to_be_picked_for_test = path;
 }
 
 // static
 void EntryPicker::SkipPickerAndAlwaysCancelForTest() {
   g_skip_picker_for_test = true;
   g_path_to_be_picked_for_test = NULL;
 }
 
 // static
 void EntryPicker::StopSkippingPickerForTest() {
   g_skip_picker_for_test = false;
 }
 
 }  // namespace api
 
 }  // namespace extensions