Code review comment for lp://qastaging/~woodrow-shen/gnome-screenshot/fix-hidpi.trusty

Hey Woodrow, thanks for your work on that, some comments:

- is that work coming from upstream? if not could we forward them the change, it's not Ubuntu specific and we would benefit to see it reviewed/commited to the official vcs

- could you describe the change and add urls to the bugs in the patch for reference

- the bug should be fixed in vivid before being SRUed