Let test driver export json results.

tools/run-tests.py

 #!/usr/bin/env python
 #
 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 155 matching lines @@
   result.add_option("--outdir", help="Base directory with compile output",
                     default="out")
   result.add_option("-p", "--progress",
                     help=("The style of progress indicator"
                           " (verbose, dots, color, mono)"),
                     choices=progress.PROGRESS_INDICATORS.keys(), default="mono")
   result.add_option("--quickcheck", default=False, action="store_true",
                     help=("Quick check mode (skip slow/flaky tests)"))
   result.add_option("--report", help="Print a summary of the tests to be run",
                     default=False, action="store_true")
+  result.add_option("--json-test-results",
+                    help="Path to a file for storing json results.")
   result.add_option("--shard-count",
                     help="Split testsuites into this number of shards",
                     default=1, type="int")
   result.add_option("--shard-run",
                     help="Run this shard from the split up tests.",
                     default=1, type="int")
   result.add_option("--shell", help="DEPRECATED! use --shell-dir", default="")
   result.add_option("--shell-dir", help="Directory containing executables",
                     default="")
   result.add_option("--dont-skip-slow-simulator-tests",
@@ skipping 270 matching lines @@
   if num_tests == 0:
     print "No tests to run."
     return 0
 
   # Run the tests, either locally or distributed on the network.
   start_time = time.time()
   progress_indicator = progress.PROGRESS_INDICATORS[options.progress]()
   if options.junitout:
     progress_indicator = progress.JUnitTestProgressIndicator(
         progress_indicator, options.junitout, options.junittestsuite)
+  if options.json_test_results:
+    progress_indicator = progress.JsonTestProgressIndicator(
+        progress_indicator, options.json_test_results, arch, mode)
 
   run_networked = not options.no_network
   if not run_networked:
     print("Network distribution disabled, running tests locally.")
   elif utils.GuessOS() != "linux":
     print("Network distribution is only supported on Linux, sorry!")
     run_networked = False
   peers = []
   if run_networked:
     peers = network_execution.GetPeers()
@@ skipping 16 matching lines @@
   exit_code = runner.Run(options.j)
   overall_duration = time.time() - start_time
 
   if options.time:
     verbose.PrintTestDurations(suites, overall_duration)
   return exit_code
 
 
 if __name__ == "__main__":
   sys.exit(Main())