views: Factor out Listener from Combobox into its own header file.

chrome/browser/chromeos/options/vpn_config_view.cc

 // Copyright (c) 2011 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/chromeos/options/vpn_config_view.h"
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/common/net/x509_certificate_model.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/locale_settings.h"
 #include "grit/theme_resources.h"
 #include "net/base/cert_database.h"
 #include "net/base/x509_certificate.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/combobox_model.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/views/layout/grid_layout.h"
 #include "ui/views/layout/layout_constants.h"
+#include "views/controls/combobox/combobox.h"
 #include "views/controls/label.h"
 #include "views/controls/textfield/textfield.h"
 
 namespace {
 
 // Root CA certificates that are built into Chrome use this token name.
 const char* const kRootCertificateTokenName = "Builtin Object Token";
 
 string16 ProviderTypeToString(chromeos::ProviderType type) {
   switch (type) {
@@ skipping 718 matching lines @@
     return std::string();
   std::string untrimmed = UTF16ToUTF8(textfield->text());
   if (!trim_whitespace)
     return untrimmed;
   std::string result;
   TrimWhitespaceASCII(untrimmed, TRIM_ALL, &result);
   return result;
 }
 
 }  // namespace chromeos