CSSPropertyTextOverFlow is currently listed as unimplemented in in \WebCore\css\CSSComputedStyleDeclaration.cpp, and is not visible in the object returned by getComputedStyle object or (consequently) in the Web Inspector.
Created attachment 33353 [details] Patch to expose the value of text-overflow on the computedStyle object.
committed with r46285 (http://trac.webkit.org/changeset/46285)
<rdar://problem/7227096>