Use a ui::MenuModel in views::Combobox

ui/views/controls/menu/menu_controller.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/controls/menu/menu_controller.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/rtl.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
@@ skipping 1628 matching lines @@
 gfx::Rect MenuController::CalculateMenuBounds(MenuItemView* item,
                                               bool prefer_leading,
                                               bool* is_leading) {
   DCHECK(item);
 
   SubmenuView* submenu = item->GetSubmenu();
   DCHECK(submenu);
 
   gfx::Size pref = submenu->GetScrollViewContainer()->GetPreferredSize();
 
+  // For comboboxes, ensure the menu is at least as wide as the anchor.
+  if (is_combobox_)
+    pref.set_width(std::max(pref.width(), state_.initial_bounds.width()));
+
   // Don't let the menu go too wide.
   pref.set_width(std::min(pref.width(),
                             item->GetDelegate()->GetMaxWidthForMenu(item)));
   if (!state_.monitor_bounds.IsEmpty())
     pref.set_width(std::min(pref.width(), state_.monitor_bounds.width()));
 
   // Assume we can honor prefer_leading.
   *is_leading = prefer_leading;
 
   int x, y;
@@ skipping 707 matching lines @@
   }
 }
 
 gfx::Screen* MenuController::GetScreen() {
   Widget* root = owner_ ? owner_->GetTopLevelWidget() : NULL;
   return root ? gfx::Screen::GetScreenFor(root->GetNativeView())
               : gfx::Screen::GetNativeScreen();
 }
 
 }  // namespace views