The activities we define are effectively a public API that we are exporting, so we need to be thoughtful about naming issues.  My first impulse here was that we should use 'allowCrop' instead of 'crop' because setting this region doesn't force cropping; it just allows the user to crop.

On the other hand, the other arguments we support are type, width and height, and those are single short words, so 'crop' fits in well.

What do you think?