diff --git a/audio/test/low_bandwidth_audio_test.py b/audio/test/low_bandwidth_audio_test.py
index cf90476..c995cd6 100755
--- a/audio/test/low_bandwidth_audio_test.py
+++ b/audio/test/low_bandwidth_audio_test.py
@@ -56,7 +56,7 @@
   parser.add_argument('--adb-path', help='Path to adb binary.', default='adb')
   parser.add_argument('--num-retries', default='0',
                       help='Number of times to retry the test on Android.')
-  parser.add_argument('--isolated_script_test_perf_output', default=None,
+  parser.add_argument('--isolated-script-test-perf-output', default=None,
       help='Path to store perf results in histogram proto format.')
   parser.add_argument('--extra-test-args', default=[], action='append',
       help='Extra args to path to the test binary.')
diff --git a/tools_webrtc/flags_compatibility.py b/tools_webrtc/flags_compatibility.py
new file mode 100644
index 0000000..8265537
--- /dev/null
+++ b/tools_webrtc/flags_compatibility.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+import argparse
+import logging
+import subprocess
+import sys
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--isolated-script-test-perf-output')
+  args, unrecognized_args = parser.parse_known_args()
+
+  test_command = _ForcePythonInterpreter(unrecognized_args)
+  if args.isolated_script_test_perf_output:
+    test_command += ['--isolated_script_test_perf_output',
+                     args.isolated_script_test_perf_output]
+  logging.info('Running %r', test_command)
+
+  return subprocess.call(test_command)
+
+
+def _ForcePythonInterpreter(cmd):
+  """Returns the fixed command line to call the right python executable."""
+  out = cmd[:]
+  if out[0] == 'python':
+    out[0] = sys.executable
+  elif out[0].endswith('.py'):
+    out.insert(0, sys.executable)
+  return out
+
+
+if __name__ == '__main__':
+  # pylint: disable=W0101
+  logging.basicConfig(level=logging.INFO)
+  sys.exit(main())
diff --git a/tools_webrtc/gtest-parallel-wrapper.py b/tools_webrtc/gtest-parallel-wrapper.py
index ec3b8b4..fa37c5d 100755
--- a/tools_webrtc/gtest-parallel-wrapper.py
+++ b/tools_webrtc/gtest-parallel-wrapper.py
@@ -15,18 +15,25 @@
 flags. Developers should execute gtest-parallel directly.
 
 In particular, this translates the GTEST_SHARD_INDEX and GTEST_TOTAL_SHARDS
-environment variables to the --shard_index and --shard_count flags, and
-interprets e.g. --workers=2x as 2 workers per core.
+environment variables to the --shard_index and --shard_count flags
+and interprets e.g. --workers=2x as 2 workers per core.
 
 Flags before '--' will be attempted to be understood as arguments to
 gtest-parallel. If gtest-parallel doesn't recognize the flag or the flag is
 after '--', the flag will be passed on to the test executable.
 
+--isolated-script-test-perf-output is renamed to
+--isolated_script_test_perf_output. The Android test runner needs the flag to
+be in the former form, but our tests require the latter, so this is the only
+place we can do it.
+
 If the --store-test-artifacts flag is set, an --output_dir must be also
 specified.
+
 The test artifacts will then be stored in a 'test_artifacts' subdirectory of the
 output dir, and will be compressed into a zip file once the test finishes
 executing.
+
 This is useful when running the tests in swarming, since the output directory
 is not known beforehand.
 
@@ -37,6 +44,7 @@
       --another_flag \
       --output_dir=SOME_OUTPUT_DIR \
       --store-test-artifacts
+      --isolated-script-test-perf-output=SOME_OTHER_DIR \
       -- \
       --foo=bar \
       --baz
@@ -47,11 +55,13 @@
       --shard_index 0 \
       --shard_count 1 \
       --output_dir=SOME_OUTPUT_DIR \
+      --dump_json_test_results=SOME_DIR \
       some_test \
       -- \
       --test_artifacts_dir=SOME_OUTPUT_DIR/test_artifacts \
       --some_flag=some_value \
       --another_flag \
+      --isolated_script_test_perf_output=SOME_OTHER_DIR \
       --foo=bar \
       --baz
 
@@ -146,8 +156,16 @@
 
   options, unrecognized_args = parser.parse_known_args(argv)
 
-  # Just pass on flags we don't recognize to the test binary.
-  executable_args = options.executable_args + unrecognized_args
+  args_to_pass = []
+  for arg in unrecognized_args:
+    if arg.startswith('--isolated-script-test-perf-output'):
+      arg_split = arg.split('=')
+      assert len(arg_split) == 2, 'You must use the = syntax for this flag.'
+      args_to_pass.append('--isolated_script_test_perf_output=' + arg_split[1])
+    else:
+      args_to_pass.append(arg)
+
+  executable_args = options.executable_args + args_to_pass
 
   if options.store_test_artifacts:
     assert options.output_dir, (
diff --git a/tools_webrtc/gtest_parallel_wrapper_test.py b/tools_webrtc/gtest_parallel_wrapper_test.py
index 60c496c..26135e1 100755
--- a/tools_webrtc/gtest_parallel_wrapper_test.py
+++ b/tools_webrtc/gtest_parallel_wrapper_test.py
@@ -133,7 +133,7 @@
       result = gtest_parallel_wrapper.ParseArgs([
           'some_test', '--some_flag=some_value', '--another_flag',
           '--output_dir=' + output_dir, '--store-test-artifacts',
-          '--isolated_script_test_perf_output=SOME_OTHER_DIR', '--foo=bar',
+          '--isolated-script-test-perf-output=SOME_OTHER_DIR', '--foo=bar',
           '--baz'
       ])
       expected_artifacts_dir = os.path.join(output_dir, 'test_artifacts')
diff --git a/tools_webrtc/mb/mb.py b/tools_webrtc/mb/mb.py
index f332a46..6287ca2 100755
--- a/tools_webrtc/mb/mb.py
+++ b/tools_webrtc/mb/mb.py
@@ -855,6 +855,10 @@
                   '--logcat-output-file', '${ISOLATED_OUTDIR}/logcats',
                   '--store-tombstones']
     else:
+      if test_type == 'raw':
+        cmdline.append('../../tools_webrtc/flags_compatibility.py')
+        extra_files.append('../../tools_webrtc/flags_compatibility.py')
+
       if isolate_map[target].get('use_webcam', False):
         cmdline.append('../../tools_webrtc/ensure_webcam_is_running.py')
         extra_files.append('../../tools_webrtc/ensure_webcam_is_running.py')
diff --git a/tools_webrtc/mb/mb_unittest.py b/tools_webrtc/mb/mb_unittest.py
index 7633dfe..c1e477c 100755
--- a/tools_webrtc/mb/mb_unittest.py
+++ b/tools_webrtc/mb/mb_unittest.py
@@ -453,9 +453,11 @@
     self.assertEqual(files, [
         '../../.vpython',
         '../../testing/test_env.py',
+        '../../tools_webrtc/flags_compatibility.py',
         'base_unittests',
     ])
     self.assertEqual(command, [
+        '../../tools_webrtc/flags_compatibility.py',
         '../../testing/test_env.py',
         './base_unittests',
         '--asan=0',