Set the default action on the title bar menu properly on Windows.

ui/views/win/hwnd_message_handler.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 "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <shellapi.h>
 
 #include "base/bind.h"
@@ skipping 1435 matching lines @@
   bool is_restored = !is_fullscreen && !is_minimized && !is_maximized;
 
   ScopedRedrawLock lock(this);
   EnableMenuItemByCommand(menu, SC_RESTORE, is_minimized || is_maximized);
   EnableMenuItemByCommand(menu, SC_MOVE, is_restored);
   EnableMenuItemByCommand(menu, SC_SIZE, delegate_->CanResize() && is_restored);
   EnableMenuItemByCommand(menu, SC_MAXIMIZE, delegate_->CanMaximize() &&
                           !is_fullscreen && !is_maximized);
   EnableMenuItemByCommand(menu, SC_MINIMIZE, delegate_->CanMaximize() &&
                           !is_minimized);
+
+  ::SetMenuDefaultItem(menu, is_maximized ? SC_RESTORE : SC_MAXIMIZE, FALSE);
 }
 
 void HWNDMessageHandler::OnInputLangChange(DWORD character_set,
                                            HKL input_language_id) {
   delegate_->HandleInputLanguageChange(character_set, input_language_id);
 }
 
 LRESULT HWNDMessageHandler::OnKeyEvent(UINT message,
                                        WPARAM w_param,
                                        LPARAM l_param) {
@@ skipping 775 matching lines @@
   SetMsgHandled(FALSE);
 }
 
 void HWNDMessageHandler::HandleTouchEvents(const TouchEvents& touch_events) {
   base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
   for (size_t i = 0; i < touch_events.size() && ref; ++i)
     delegate_->HandleTouchEvent(touch_events[i]);
 }
 
 }  // namespace views