midori needs a granite USE flag for --enable-granite.
it was disabled purposely because midori was incompatible with the only release of libgranite at the time, 0.1.0 have you checked if midori actually works with newer ones, like 0.2.1? or is this unresearched request?
midori works with at least 0.2.1, 0.2.2, and 9999.
added to ebuild of 0.5.7