Code review comment for lp:~michihenning/thumbnailer/snap

I've added a few inline comments.

These are the changes I made while testing out the snap: http://paste.ubuntu.com/23873664/. With those changes, I tried using my second snap to access the thumbnailer:

  $ sudo snap install --dangerous thumbnailer-admin-test_0.1_amd64.snap
  $ sudo connect thumbnailer-admin-test:thumbnailer thumbnailer:thumbnailer
  $ thumbnailer-admin-test.admin get-album Radiohead 'Ok Computer'
  thumbnailer-admin: Handler::createFinished(): could not get thumbnail for album: Radiohead/Ok Computer (0,0): ERROR

On the service side, I got the following:

  $ thumbnailer.thumbnailer-service
  thumbnailer-service: [15:57:10.144] Initializing
  thumbnailer-service: [15:57:10.440] image cache: 0 entries, 0 bytes, hit rate 0.00 (0/0), avg hit run 0.00, avg miss run 0.00
  thumbnailer-service: [15:57:10.440] thumbnail cache: 0 entries, 0 bytes, hit rate 0.00 (0/0), avg hit run 0.00, avg miss run 0.00
  thumbnailer-service: [15:57:10.440] failure cache: 0 entries, 0 bytes, hit rate 0.00 (0/0), avg hit run 0.00, avg miss run 0.00

  (process:13511): GdkPixbuf-WARNING **: Cannot open pixbuf loader module file '/home/james/snap/thumbnailer/x1/.cache/gdk-pixbuf-loaders.cache': No such file or directory

  This likely means that your installation is broken.
  Try running the command
    gdk-pixbuf-query-loaders > /home/james/snap/thumbnailer/x1/.cache/gdk-pixbuf-loaders.cache
to make things work again for the time being.

  (process:13511): GdkPixbuf-WARNING **: Cannot open pixbuf loader module file '/home/james/snap/thumbnailer/x1/.cache/gdk-pixbuf-loaders.cache': No such file or directory

  This likely means that your installation is broken.
  Try running the command
    gdk-pixbuf-query-loaders > /home/james/snap/thumbnailer/x1/.cache/gdk-pixbuf-loaders.cache
to make things work again for the time being.
  thumbnailer-service: [15:57:30.227] Warning: "Handler::createFinished(): could not get thumbnail for album: Radiohead/Ok Computer (0,0): ERROR"

So it is still not quite right. It looks like there is some support for gdk-pixbuf in the desktop-launch script, but it only comes into play if we ship gdk-pixbuf plus loaders as part of our snap.