diff --git a/mojo/tools/run_mojo_python_tests.py b/mojo/tools/run_mojo_python_tests.py
index c96aba36d2cd0..fff10e3b31624 100755
--- a/mojo/tools/run_mojo_python_tests.py
+++ b/mojo/tools/run_mojo_python_tests.py
@@ -3,29 +3,39 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import optparse
+import argparse
+import json
 import os
 import re
 import sys
+import time
 import unittest
 
 
 def main():
-  parser = optparse.OptionParser()
+  parser = argparse.ArgumentParser()
   parser.usage = 'run_mojo_python_tests.py [options] [tests...]'
-  parser.add_option('-v', '--verbose', action='count', default=0)
-  parser.add_option('--unexpected-failures', metavar='FILENAME', action='store',
-                    help=('path to write a list of any tests that fail '
-                          'unexpectedly.'))
-  parser.epilog = ('If --unexpected-failures is passed, a list of the tests '
-                   'that failed (one per line) will be written to the file. '
-                   'If no tests failed, the file will be truncated (empty). '
-                   'If the test run did not completely properly, or something '
-                   'else weird happened, any existing file will be left '
-                   'unmodified. '
-                   'If --unexpected-failures is *not* passed, any existing '
-                   'file will be ignored and left unmodified.')
-  options, args = parser.parse_args()
+  parser.add_argument('-v', '--verbose', action='count', default=0)
+  parser.add_argument('--metadata', action='append', default=[],
+                      help=('optional key=value metadata that will be stored '
+                            'in the results files (can be used for revision '
+                            'numbers, etc.)'))
+  parser.add_argument('--write-full-results-to', metavar='FILENAME',
+                      action='store',
+                      help='path to write the list of full results to.')
+  parser.add_argument('tests', nargs='*')
+
+  args = parser.parse_args()
+
+  bad_metadata = False
+  for val in args.metadata:
+    if '=' not in val:
+      print >> sys.stderr, ('Error: malformed metadata "%s"' % val)
+      bad_metadata = True
+  if bad_metadata:
+    print >> sys.stderr
+    parser.print_help()
+    return 2
 
   chromium_src_dir = os.path.join(os.path.dirname(__file__),
                                   os.pardir,
@@ -36,38 +46,102 @@ def main():
 
   pylib_dir = os.path.join(chromium_src_dir, 'mojo', 'public',
                            'tools', 'bindings', 'pylib')
-  if args:
-    if not pylib_dir in sys.path:
-        sys.path.append(pylib_dir)
+  if args.tests:
+    if pylib_dir not in sys.path:
+      sys.path.append(pylib_dir)
     suite = unittest.TestSuite()
     for test_name in args:
       suite.addTests(loader.loadTestsFromName(test_name))
   else:
     suite = loader.discover(pylib_dir, pattern='*_unittest.py')
 
-  runner = unittest.runner.TextTestRunner(verbosity=(options.verbose + 1))
+  runner = unittest.runner.TextTestRunner(verbosity=(args.verbose + 1))
   result = runner.run(suite)
 
-  if options.unexpected_failures:
-    WriteUnexpectedFailures(result, options.unexpected_failures)
+  full_results = _FullResults(suite, result, args.metadata)
+  if args.write_full_results_to:
+    with open(args.write_full_results_to, 'w') as fp:
+      json.dump(full_results, fp, indent=2)
+      fp.write("\n")
 
   return 0 if result.wasSuccessful() else 1
 
 
-def WriteUnexpectedFailures(result, path):
+TEST_SEPARATOR = '.'
 
+
+def _FullResults(suite, result, metadata):
+  """Convert the unittest results to the Chromium JSON test result format.
+
+  This matches run-webkit-tests (the layout tests) and the flakiness dashboard.
+  """
+
+  full_results = {}
+  full_results['interrupted'] = False
+  full_results['path_delimiter'] = TEST_SEPARATOR
+  full_results['version'] = 3
+  full_results['seconds_since_epoch'] = time.time()
+  for md in metadata:
+    key, val = md.split('=', 1)
+    full_results[key] = val
+
+  all_test_names = _AllTestNames(suite)
+  failed_test_names = _FailedTestNames(result)
+
+  full_results['num_failures_by_type'] = {
+      'Failure': len(failed_test_names),
+      'Pass': len(all_test_names) - len(failed_test_names),
+  }
+
+  full_results['tests'] = {}
+
+  for test_name in all_test_names:
+    value = {
+        'expected': 'PASS',
+        'actual': 'FAIL' if (test_name in failed_test_names) else 'FAIL',
+    }
+    _AddPathToTrie(full_results['tests'], test_name, value)
+
+  return full_results
+
+
+def _AllTestNames(suite):
+  test_names = []
+  # _tests is protected  pylint: disable=W0212
+  for test in suite._tests:
+    if isinstance(test, unittest.suite.TestSuite):
+      test_names.extend(_AllTestNames(test))
+    else:
+      test_names.append(_UnitTestName(test))
+  return test_names
+
+
+def _FailedTestNames(result):
+  failed_test_names = set()
+  for (test, _) in result.failures + result.errors:
+    failed_test_names.add(_UnitTestName(test))
+  return failed_test_names
+
+
+def _AddPathToTrie(trie, path, value):
+  if TEST_SEPARATOR not in path:
+    trie[path] = value
+    return
+  directory, rest = path.split(TEST_SEPARATOR, 1)
+  if directory not in trie:
+    trie[directory] = {}
+  _AddPathToTrie(trie[directory], rest, value)
+
+
+_UNITTEST_NAME_REGEX = re.compile("(\w+) \(([\w.]+)\)")
+
+
+def _UnitTestName(test):
   # This regex and UnitTestName() extracts the test_name in a way
   # that can be handed back to the loader successfully.
-
-  test_description = re.compile("(\w+) \(([\w.]+)\)")
-
-  def UnitTestName(test):
-    m = test_description.match(str(test))
-    return "%s.%s" % (m.group(2), m.group(1))
-
-  with open(path, 'w') as fp:
-    for (test, _) in result.failures + result.errors:
-      fp.write(UnitTestName(test) + '\n')
+  m = _UNITTEST_NAME_REGEX.match(str(test))
+  assert m, "could not find test name from test description %s" % str(test)
+  return "%s.%s" % (m.group(2), m.group(1))
 
 
 if __name__ == '__main__':