Update from https://crrev.com/316786

tools/clang/scripts/update.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Windows can't run .sh files, so this is a Python implementation of
 update.sh. This script should replace update.sh on all platforms eventually."""
 
 import os
 import re
 import shutil
 import subprocess
 import stat
 import sys
 import time
 
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
 # Note: this revision is only used for Windows. Other platforms use update.sh.
 LLVM_WIN_REVISION = 'HEAD'
 
 # ASan on Windows is useful enough to use it even while the clang/win is still
 # in bringup. Use a pinned revision to make it slightly more stable.
 if (re.search(r'\b(asan)=1', os.environ.get('GYP_DEFINES', '')) and
     not 'LLVM_FORCE_HEAD_REVISION' in os.environ):
-  LLVM_WIN_REVISION = '226810'
+  LLVM_WIN_REVISION = '228702'
 
 # Path constants. (All of these should be absolute paths.)
 THIS_DIR = os.path.abspath(os.path.dirname(__file__))
 CHROMIUM_DIR = os.path.abspath(os.path.join(THIS_DIR, '..', '..', '..'))
 LLVM_DIR = os.path.join(CHROMIUM_DIR, 'third_party', 'llvm')
 LLVM_BUILD_DIR = os.path.join(CHROMIUM_DIR, 'third_party', 'llvm-build',
                               'Release+Asserts')
 COMPILER_RT_BUILD_DIR = os.path.join(LLVM_BUILD_DIR, '32bit-compiler-rt')
 CLANG_DIR = os.path.join(LLVM_DIR, 'tools', 'clang')
 LLD_DIR = os.path.join(LLVM_DIR, 'tools', 'lld')
@@ skipping 236 matching lines @@
 
   if re.search(r'\b(make_clang_dir)=', os.environ.get('GYP_DEFINES', '')):
     print 'Skipping Clang update (make_clang_dir= was set in GYP_DEFINES).'
     return 0
 
   return UpdateClang()
 
 
 if __name__ == '__main__':
   sys.exit(main())