Adding io_timeout to our swarming tests.

tools/perf/generate_perf_json.py

 #!/usr/bin/env python
 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Script to generate chromium.perf.json and chromium.perf.fyi.json in
 the src/testing/buildbot directory. Maintaining these files by hand is
 too unwieldy.
 """
 
@@ skipping 432 matching lines @@
   }
   if override_compile_targets:
     result['override_compile_targets'] = override_compile_targets
   if swarming_dimensions:
     result['swarming'] = {
       # Always say this is true regardless of whether the tester
       # supports swarming. It doesn't hurt.
       'can_use_on_swarming_builders': True,
       'expiration': 21600,
       'hard_timeout': 7200,
+      'io_timeout': 3600,
       'dimension_sets': swarming_dimensions,
     }
   return result
 
 
 def generate_telemetry_test(swarming_dimensions, benchmark_name, browser):
   # The step name must end in 'test' or 'tests' in order for the
   # results to automatically show up on the flakiness dashboard.
   # (At least, this was true some time ago.) Continue to use this
   # naming convention for the time being to minimize changes.
@@ skipping 283 matching lines @@
   waterfall['name'] = 'chromium.perf'
   fyi_waterfall = get_fyi_waterfall_config()
   fyi_waterfall['name'] = 'chromium.perf.fyi'
 
   generate_all_tests(fyi_waterfall)
   generate_all_tests(waterfall)
   return 0
 
 if __name__ == '__main__':
   sys.exit(main())