Behavior in flight mode is too slow

[Michi Henning]

With the phone in flight mode, I drop two songs into the Music directory (with a cold cache). Both songs are tagged correctly, but do not include artwork.

When starting the music app, I see this in the log:

thumbnailer-service: [00:41:46.960] "album: Pink Floyd/The Dark Side Of The Moon [2011 - Remaster] (108,108): 10.193014 [q: 0.000030, d: 10.085941] sec (NETWORK DOWN)"
thumbnailer-service: [00:41:46.985] "album: Mamady Keïta/Afö (108,108): 10.237612 [d: 10.096038] sec (NETWORK DOWN)"
thumbnailer-service: [00:41:56.944] "album: Pink Floyd/ (512,512): 20.117857 [q: 10.050250, d: 9.999093] sec (NETWORK DOWN)"
thumbnailer-service: [00:41:56.966] "album: Pink Floyd/The Dark Side Of The Moon [2011 - Remaster] (512,512): 20.132530 [q: 10.036004, d: 9.999032] sec (NETWORK DOWN)"
thumbnailer-service: [00:42:06.944] "album: Mamady Keïta/ (512,512): 30.077019 [q: 20.011791, d: 10.000526] sec (NETWORK DOWN)"
thumbnailer-service: [00:42:06.967] "album: Mamady Keïta/Afö (512,512): 30.091875 [q: 20.002243, d: 10.000587] sec (NETWORK DOWN)"
thumbnailer-service: [00:42:16.933] "album: Pink Floyd/The Dark Side Of The Moon [2011 - Remaster] (512,512): 40.024223 [q: 19.896146, d: 10.000160] sec (NETWORK DOWN)"

It takes us a full 10 seconds to realize that the network is down, and that is repeatedly for each request (as shown by the download time stamps above (labelled "d:").

We need to

1) Figure out a way to realize quickly that the network is down.

2) If the network is down, remember that fact for at least 30 seconds or so and, during that time, fail requests immediately.

[PS Jenkins bot (ps-jenkins)]

Fix committed into lp:thumbnailer/devel at revision 240, scheduled for release in thumbnailer, milestone Unknown