Add an equals method to Contact.
A contact is equals to an other if they got the same bare Jid.
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group>
<item android:id="@+id/chat_menu_contacts_list" android:visible="true"
android:title="@string/chat_menu_contacts_list" android:icon="@drawable/ic_menu_friendslist" />
<item android:id="@+id/chat_menu_change_chat" android:visible="true"
android:title="@string/chat_menu_change_chat" android:icon="@drawable/ic_menu_chat_dashboard" />
</group>
<item android:id="@+id/chat_menu_close_chat" android:visible="true"
android:title="@string/chat_menu_close_chat" android:icon="@drawable/ic_menu_end_conversation" />
</menu>