Switch VS 2017 builds to VS 2017 Update 3 Preview 1

build/vs_toolchain.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 import glob
 import json
 import os
 import pipes
 import platform
@@ skipping 324 matching lines @@
 
 
 def _GetDesiredVsToolchainHashes():
   """Load a list of SHA1s corresponding to the toolchains that we want installed
   to build with."""
   env_version = GetVisualStudioVersion()
   if env_version == '2015':
     # Update 3 final with patches with 10.0.14393.0 SDK.
     return ['d3cb0e37bdd120ad0ac4650b674b09e81be45616']
   if env_version == '2017':
-    # VS 2017 RTM with 10.0.14393.0 SDK and dbghelp.dll fixes.
-    return ['4e8a360587a3c8ff3fa46aa9271e982bf3e948ec']
+    # VS 2017 Update 3 Preview 1 with 10.0.14393.0 SDK and patched statreg.h.
+    return ['3915730f76bd9c6155aed871b944b0a25c18f15e']
   raise Exception('Unsupported VS version %s' % env_version)
 
 
 def ShouldUpdateToolchain():
   """Check if the toolchain should be upgraded."""
   if not os.path.exists(json_data_file):
     return True
   with open(json_data_file, 'r') as tempf:
     toolchain_data = json.load(tempf)
   version = toolchain_data['version']
@@ skipping 83 matching lines @@
       'copy_dlls': CopyDlls,
   }
   if len(sys.argv) < 2 or sys.argv[1] not in commands:
     print >>sys.stderr, 'Expected one of: %s' % ', '.join(commands)
     return 1
   return commands[sys.argv[1]](*sys.argv[2:])
 
 
 if __name__ == '__main__':
   sys.exit(main())