Run telemetry_unitests in serial

testing/buildbot/gn_isolate_map.pyl

 ## Copyright 2015 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.
 
 # gn_isolate_map.pyl - A mapping of Ninja build target names to GN labels and
 # test type classifications for the tests that are run on the bots.
 #
 # This mapping is used by MB so that we can uniformly refer to test binaries
 # by their Ninja target names in the recipes and not need to worry about how
 # they are referred to in GN or GYP specifically (the GYP target name is pretty
@@ skipping 819 matching lines @@
     ],
   },
   "telemetry_unittests": {
     "label": "//chrome/test:telemetry_unittests",
     "type": "script",
     "script": "//testing/scripts/run_telemetry_as_googletest.py",
     "args": [
       "--xvfb",
       "../../tools/perf/run_telemetry_tests",
       "-v",
+      # TODO(nedn, eyaich): Remove this flag once crbug.com/549140 is fixed &
+      # Telemetry no longer downloads files in parallel. (crbug.com/661434#c24)
+      "--jobs=1",
       "--chrome-root",
       "../../",
     ],
   },
   "cc_perftests": {
     "label": "//cc:cc_perftests",
     "type": "script",
     "script": "//testing/scripts/run_gtest_perf_test.py",
     "args": [
       "cc_perftests",
@@ skipping 136 matching lines @@
   },
   "wm_unittests": {
     "label": "//ui/wm:wm_unittests",
     "type": "windowed_test_launcher",
   },
   "wtf_unittests": {
     "label": "//third_party/WebKit/Source/wtf:wtf_unittests",
     "type": "console_test_launcher",
   },
 }