Add dummy implemenation of accelerator_util for Windows.

atom.gyp

@@ -35,6 +35,7 @@
       'browser/accelerator_util.cc',
       'browser/accelerator_util.h',
       'browser/accelerator_util_mac.mm',
+      'browser/accelerator_util_win.cc',
       'browser/api/atom_api_app.cc',
       'browser/api/atom_api_app.h',
       'browser/api/atom_api_auto_updater.cc',

browser/accelerator_util_win.cc

@@ -0,0 +1,14 @@
+// Copyright (c) 2013 GitHub, Inc. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "browser/accelerator_util.h"
+
+#include "ui/base/accelerators/accelerator.h"
+
+namespace accelerator_util {
+
+void SetPlatformAccelerator(ui::Accelerator* accelerator) {
+}
+
+}  // namespace accelerator_util