STR: 1. Launch latest nightly 2. Look for screenshot icon in toolbar 3. Go to customize and look for screen shot icon Actual: There is no screenshot tool Expected: Screenshot tool should be there. I did mozregression and found following regression range: Last good revision: 1b4c59eef820b46eb0037aca68f83a15088db45f (2017-08-29) First bad revision: ab2d700fda2b4934d24227216972dce9fac19b74 (2017-08-30) 6:30.71 Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1b4c59eef820b46eb0037aca68f83a15088db45f&tochange=ab2d700fda2b4934d24227216972dce9fac19b74 I couldn't bisect it further.

The screenshots item moved to the page action menu when bug 1390985 landed.