[Windows] Clear Browsing Data dialog should not have any button as default action.

chrome/browser/views/clear_browsing_data.cc

 // Copyright (c) 2006-2008 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/views/clear_browsing_data.h"
 
 #include "app/l10n_util.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/search_engines/template_url_model.h"
 #include "chrome/common/pref_names.h"
@@ skipping 226 matching lines @@
     } else {
       parent->RemoveChildView(&status_label_);
       parent->RemoveChildView(throbber_.get());
     }
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ClearBrowsingDataView, views::DialogDelegate implementation:
 
+int ClearBrowsingDataView::GetDefaultDialogButton() const {
+  return MessageBoxFlags::DIALOGBUTTON_NONE;
+}
+
 std::wstring ClearBrowsingDataView::GetDialogButtonLabel(
     MessageBoxFlags::DialogButton button) const {
   if (button == MessageBoxFlags::DIALOGBUTTON_OK) {
     return l10n_util::GetString(IDS_CLEAR_BROWSING_DATA_COMMIT);
   } else if (button == MessageBoxFlags::DIALOGBUTTON_CANCEL) {
     return l10n_util::GetString(IDS_CLOSE);
   } else {
     return std::wstring();
   }
 }
@@ skipping 175 matching lines @@
   remover_->AddObserver(this);
   remover_->Remove(remove_mask);
 }
 
 void ClearBrowsingDataView::OnBrowsingDataRemoverDone() {
   // No need to remove ourselves as an observer as BrowsingDataRemover deletes
   // itself after we return.
   remover_ = NULL;
   window()->Close();
 }