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

chrome/browser/views/clear_browsing_data.cc

Index: chrome/browser/views/clear_browsing_data.cc
===================================================================
--- chrome/browser/views/clear_browsing_data.cc	(revision 25841)
+++ chrome/browser/views/clear_browsing_data.cc	(working copy)
@@ -244,6 +244,10 @@
 ////////////////////////////////////////////////////////////////////////////////
 // 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) {