The dropzone attribute is being removed from the HTML specification in whatwg/html#2402 and should be removed from WPT. This is not a trivial find-and-remove because we need to make sure that the tests we remove aren't intended to cover other functionality.

For example, Blink had tests that used dropzone and also covered the interaction between DataTransfer.effectAllowed and DataTransfer.dropEffect, which had to be rewritten in https://codereview.chromium.org/2729353002/

This issue will track my efforts to sift through all tests that contain dropzone and update or remove them.