Refactor: move wxComboBox::MSWDoPopupOrDismiss() down to wxChoice.

No real changes, just make this method available in wxChoice for the next
commit needs.

See #3113.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71103 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/combobox.cpp

@@ -642,22 +642,6 @@ void wxComboBox::OnUpdateSelectAll(wxUpdateUIEvent& event)
     event.Enable(IsEditable() && !wxTextEntry::IsEmpty());
 }
 
-void wxComboBox::MSWDoPopupOrDismiss(bool show)
-{
-    wxASSERT_MSG( !HasFlag(wxCB_SIMPLE),
-                  wxT("can't popup/dismiss the list for simple combo box") );
-
-    // we *must* set focus to the combobox before showing or hiding the drop
-    // down as without this we get WM_LBUTTONDOWN messages with invalid HWND
-    // when hiding it (whether programmatically or manually) resulting in a
-    // crash when we pass them to IsDialogMessage()
-    //
-    // this can be seen in the combo page of the widgets sample under Windows 7
-    SetFocus();
-
-    ::SendMessage(GetHwnd(), CB_SHOWDROPDOWN, show, 0);
-}
-
 #if wxUSE_TOOLTIPS
 
 void wxComboBox::DoSetToolTip(wxToolTip *tip)