[infra] Fix clang-format invocation from git cl format

tools/buildtools/mac/clang-format

Index: tools/buildtools/mac/clang-format
diff --git a/tools/buildtools/mac/clang-format b/tools/buildtools/mac/clang-format
deleted file mode 100755
index 39549a91daa194249274a44c3483d42b8cf7d8b9..0000000000000000000000000000000000000000
--- a/tools/buildtools/mac/clang-format
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/usr/bin/env python
-# Copyright 2017 The Dart 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.
-
-"""Forwards to the clang-format for the MacOS toolchain."""
-
-import os
-import subprocess
-import sys
-
-DART_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-TOOLCHAIN = os.path.join(DART_ROOT, 'buildtools', 'toolchain')
-CLANG_FORMAT = os.path.join(TOOLCHAIN, 'clang+llvm-x86_64-darwin', 'bin', 'clang-format')
-
-def main(argv):
-  return subprocess.call([CLANG_FORMAT] + argv[1:])
-
-if __name__ == '__main__':
-  sys.exit(main(sys.argv))