Add script which gathers JSON output from a Swarming task's shards.

content/test/gpu/generate_buildbot_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.gpu.json and chromium.gpu.fyi.json in
 the src/testing/buildbot directory. Maintaining these files by hand is
 too unwieldy.
 """
 
@@ skipping 913 matching lines @@
           # doesn't support features needed for ES3
           'Linux Release (New Intel)',
           'Linux Debug (New Intel)',
         ],
       },
     ],
     'target_name': 'webgl_conformance',
     'args': [
       '--webgl-conformance-version=2.0.0',
       '--webgl2-only=true',
+      # The current working directory when run via isolate is
+      # out/Debug or out/Release. Reference this file relatively to
+      # it.
+      '--read-abbreviated-json-results-from=' + \
+      '../../content/test/data/gpu/webgl2_conformance_tests_output.json',
     ],
     'swarming': {
       # These tests currently take about an hour to run. Split them
       # into roughly 5-minute shards.
       'shards': 12,
     },
   },
   'webgl2_conformance_angle_tests': {
     'tester_configs': [
       {
@@ skipping 15 matching lines @@
         ],
       },
     ],
     'target_name': 'webgl_conformance',
     'extra_browser_args': [
       '--use-gl=angle',
     ],
     'args': [
       '--webgl-conformance-version=2.0.0',
       '--webgl2-only=true',
+      # The current working directory when run via isolate is
+      # out/Debug or out/Release. Reference this file relatively to
+      # it.
+      '--read-abbreviated-json-results-from=' + \
+      '../../content/test/data/gpu/webgl2_conformance_tests_output.json',
     ],
     'swarming': {
       # These tests currently take about an hour to run. Split them
       # into roughly 5-minute shards.
       'shards': 12,
     },
   },
 }
 
 def substitute_args(tester_config, args):
@@ skipping 218 matching lines @@
     json.dump(tests, fp, indent=2, separators=(',', ': '), sort_keys=True)
     fp.write('\n')
 
 def main():
   generate_all_tests(FYI_WATERFALL, True)
   generate_all_tests(WATERFALL, False)
   return 0
 
 if __name__ == "__main__":
   sys.exit(main())