Update gtest-parallel and introduce gtest-parallel-wrapper.

third_party/gtest-parallel/gtest-parallel

Index: third_party/gtest-parallel/gtest-parallel
diff --git a/third_party/gtest-parallel/gtest-parallel b/third_party/gtest-parallel/gtest-parallel
index 5c4d44e63ba885fd1cdd6c8057d814c40b2ea02e..778a29a07732364f45c3bb3d406bb65813c80087 100755
--- a/third_party/gtest-parallel/gtest-parallel
+++ b/third_party/gtest-parallel/gtest-parallel
@@ -265,16 +265,13 @@ parser.add_option('--gtest_also_run_disabled_tests', action='store_true',
 parser.add_option('--format', type='string', default='filter',
                   help='output format (raw,filter)')
 parser.add_option('--print_test_times', action='store_true', default=False,
-                  help='When done, list the run time of each test')
-parser.add_option('--shard_count', type='int',
-                  default=int(os.environ.pop('GTEST_TOTAL_SHARDS', 1)),
-                  help=('Total number of shards (for sharding test execution '
-                        'between multiple machines). Default: %default'))
-parser.add_option('--shard_index', type='int',
-                  default=int(os.environ.pop('GTEST_SHARD_INDEX', 0)),
-                  help=('Zero-indexed number identifying this shard (for '
-                        'sharding test execution between multiple machines). '
-                        'Default: %default'))
+                  help='list the run time of each test at the end of execution')
+parser.add_option('--shard_count', type='int', default=1,
+                  help='total number of shards (for sharding test execution '
+                       'between multiple machines)')
+parser.add_option('--shard_index', type='int', default=0,
+                  help='zero-indexed number identifying this shard (for '
+                       'sharding test execution between multiple machines)')
 
 (options, binaries) = parser.parse_args()
 
@@ -288,15 +285,15 @@ if options.format == 'raw':
 elif options.format == 'filter':
   logger = FilterFormat()
 else:
-  sys.exit("Unknown output format: " + options.format)
+  parser.error("Unknown output format: " + options.format)
 
 if options.shard_count < 1:
-  sys.exit("Invalid number of shards: %d. Must be at least 1." %
-           options.shard_count)
-if options.shard_index < 0 or options.shard_count <= options.shard_index:
-  sys.exit("Invalid shard index: %d. Must be between 0 and %d." %
-           (options.shard_index, options.shard_count - 1))
-
+  parser.error("Invalid number of shards: %d. Must be at least 1." %
+               options.shard_count)
+if not (0 <= options.shard_index < options.shard_count):
+  parser.error("Invalid shard index: %d. Must be between 0 and %d "
+               "(less than the number of shards)." %
+               (options.shard_index, options.shard_count - 1))
 
 # Find tests.
 save_file = os.path.join(os.path.expanduser("~"), ".gtest-parallel-times")