Disable cc_perftests on Nexus 5X perf bot

tools/perf/core/perf_data_generator.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.
 
 # pylint: disable=too-many-lines
 
 """Script to generate chromium.perf.json and chromium.perf.fyi.json in
 the src/testing/buildbot directory and benchmark.csv in the src/tools/perf
 directory. Maintaining these files by hand is too unwieldy.
@@ skipping 245 matching lines @@
            'build74-b1--device1', 'build74-b1--device2', 'build74-b1--device3',
            'build74-b1--device4', 'build74-b1--device5', 'build74-b1--device6',
            'build74-b1--device7',
            'build75-b1--device1', 'build75-b1--device2', 'build75-b1--device3',
            'build75-b1--device4', 'build75-b1--device5', 'build75-b1--device6',
            'build75-b1--device7',
           ],
        'perf_tests': [
          ('tracing_perftests', 'build73-b1--device2'),
          ('gpu_perftests', 'build73-b1--device2'),
-         ('cc_perftests', 'build73-b1--device2'),
+         #  ('cc_perftests', 'build73-b1--device2'),  # crbug.com/721757
          ]
       }
     ])
   waterfall = add_tester(
     waterfall, 'Win 10 High-DPI Perf', 'win-high-dpi', 'win',
     swarming=[
       {
        'gpu': '8086:1616',
        'os': 'Windows-10-10240',
        'pool': 'Chrome-perf',
@@ skipping 716 matching lines @@
       return 0
     else:
       print ('The perf JSON config files are not up-to-date. Please run %s '
              'without --validate-only flag to update the perf JSON '
              'configs and benchmark.csv.') % sys.argv[0]
       return 1
   else:
     update_all_tests([fyi_waterfall, waterfall])
     update_benchmark_csv()
   return 0