MB: Run test with gtest-parallel on swarming.

tools/mb/mb.py

Index: tools/mb/mb.py
diff --git a/tools/mb/mb.py b/tools/mb/mb.py
index 038217e072b032b3b2243cd7a38ca70b008f5f21..798c54ea3761e46a88eaf540613ca976a7fff60b 100755
--- a/tools/mb/mb.py
+++ b/tools/mb/mb.py
@@ -1077,6 +1077,7 @@ class MetaBuildWrapper(object):
 
     executable = isolate_map[target].get('executable', target)
     executable_suffix = '.exe' if self.platform == 'win32' else ''
+    executable_preffix = '.\\' if self.platform == 'win32' else './'
 
     cmdline = []
     extra_files = []
@@ -1108,26 +1109,30 @@ class MetaBuildWrapper(object):
           'xdisplaycheck',
           '../../testing/test_env.py',
           '../../testing/xvfb.py',
+          '../../third_party/gtest-parallel/gtest-parallel',
       ]
       cmdline = [
         '../../testing/xvfb.py',
         '.',
-        './' + str(executable) + executable_suffix,
-        '--brave-new-test-launcher',
-        '--test-launcher-bot-mode',
+        'python',
+        '../../third_party/gtest-parallel/gtest-parallel',
+        executable_preffix + str(executable) + executable_suffix,
+        '--',
         '--asan=%d' % asan,
         '--msan=%d' % msan,
         '--tsan=%d' % tsan,
       ]
     elif test_type in ('windowed_test_launcher', 'console_test_launcher'):
       extra_files = [
-          '../../testing/test_env.py'
+          '../../testing/test_env.py',
+          '../../third_party/gtest-parallel/gtest-parallel',
       ]
       cmdline = [
           '../../testing/test_env.py',
-          './' + str(executable) + executable_suffix,
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
+          'python',
+          '../../third_party/gtest-parallel/gtest-parallel',
+          executable_preffix + str(executable) + executable_suffix,
+          '--',
           '--asan=%d' % asan,
           '--msan=%d' % msan,
           '--tsan=%d' % tsan,