Roll src/tools/swarming_client/ 9a518d097..486c9b53c (9 commits)

https://chromium.googlesource.com/infra/luci/client-py.git/+log/9a518d097dca..486c9b53c4d5

$ git log 9a518d097..486c9b53c --date=short --no-merges --format='%ad %ae %s'
2018-07-23 maruel [client] lower default task priority to 200
2018-07-23 maruel Roll infra_libs, gae_event_mon and gae_ts_mon.
2018-06-28 maruel client: fix exception on symlink
2018-06-26 martiniss Revert "Bump version of infra_libs to 1.4.0"
2018-06-25 martiniss Bump version of infra_libs to 1.4.0
2018-06-22 maruel [swarming] more task state documentation
2018-06-20 nodir Add Google RPC protobufs
2018-06-18 maruel [client] Fix regression in d335c4bf86
2018-06-18 maruel [client] Fix regression in a768d983f4

Created with:
  roll-dep src/tools/swarming_client

Bug: 855253,864655
Change-Id: Ic98b9572df6ec364afa2595802abf266e3202a46
Reviewed-on: https://chromium-review.googlesource.com/1147154Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577327}

DEPS

@@ -113,7 +113,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
-  'swarming_revision': '9a518d097dca20b7b00ce3bdfc5d418ccc79893a',
+  'swarming_revision': '486c9b53c4d54dd4b95bb6ce0e31160e600dfc11',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.