[INTERNAL] m.MessageToast: encapsulate some private methods

Change-Id: I4cf2ece7a5b073144d4a0a6eef35e5a2cbcca152
[INTERNAL] m.ComboBoxBase: better formatting of the constructor

Change-Id: I8a998af50d5a59b3733307049565a4a0efadb109
Merge "[INTERNAL] m.MessageToast: encapsulate some private methods"
Merge "[INTERNAL] m.ComboBoxBase: better formatting of the constructor"