Bug 554025

REPRO:

1. Make /uia2atk/test/samples/moonlight/CheckBox
2. Run CheckBoxSample.html and accerciser
3. On app windows, mouse click "Three State CheckBox" to indeterminate status
4. On accerciser, expend CheckBoxSample document frame and Silverlight Control
filler, select "Three State CheckBox"
5. Under interface viewer, see the checkbox's states

RESULTS:

there is missing 'indeterminate' state

EXPECTED RESULTS:

'indeterminate' state is expected when the checkbox has ThreeState property. 

INDETERMINATE STATES:
 Indicates that a check box is in a state other than checked or not checked.
 This usually means that the boolean value reflected or controlled by the
 object does not apply consistently to the entire current context. For
 example, a checkbox for the "Bold" attribute of text may have
 STATE_INDETERMINATE if the currently selected text contains a mixture of
 weight attributes. In many cases interacting with a STATE_INDETERMINATE
 object will cause the context's corresponding boolean attribute to be
 homogenized, whereupon the object will lose STATE_INDETERMINATE and a
 corresponding state-changed event will be fired.