Roll src/tools/swarming_client/ 6e5d2b21f..e4c0e242e (2 commits).
Roll src/tools/swarming_client/ 6e5d2b21f..e4c0e242e (2 commits).

https://chromium.googlesource.com/external/swarming.client.git/+log/6e5d2b21f0ac..e4c0e242eeec

$ git log 6e5d2b21f..e4c0e242e --date=short --format='%ad %ae %s'
2015-09-30 vadimsh Fix retry of bad 404 Cloud Endpoint responses.
2015-09-30 maruel Make swarming.py collect return 1 on expired task.

R=vadimsh@chromium.org
BUG=536934,522388

Review URL: https://codereview.chromium.org/1374593003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#351885}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk