At the moment when someone tells sheriffbot "sheriffbot: roll-chromium-deps" the revision log for the change says, "Unreviewed. Rolled DEPS." It should give more information, namely who requested the roll and whether it was the LKGR or not.
Created attachment 182496 [details] Patch
Comment on attachment 182496 [details] Patch LGTM.
Comment on attachment 182496 [details] Patch Clearing flags on attachment: 182496 Committed r139578: <http://trac.webkit.org/changeset/139578>
All reviewed patches have been landed. Closing bug.