Add buildtools to make depot_tools-wrapped clang-format work

DEPS

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 11 matching lines @@
       '29763965ab52f24565299976b936d1265cb6a271',  # svn r501
   'crashpad/third_party/gtest/gtest':
       Var('chromium_git') + '/external/gtest@' +
       '8245545b6dc9c4703e6496d1efd19e975ad2b038',  # svn r700
   'crashpad/third_party/gyp/gyp':
       Var('chromium_git') + '/external/gyp@' +
       '01528c7244837168a1c80f06ff60fa5a9793c824',
   'crashpad/third_party/mini_chromium/mini_chromium':
       Var('chromium_git') + '/chromium/mini_chromium@' +
       '8e12d3df2f1c0fcd84d649f4619323558db63a85',
+  'buildtools':
+      Var('chromium_git') + '/chromium/buildtools.git@' +
+      'c2f259809d5ede3275df5ea0842f0431990c4f98',
 }
 
 hooks = [
   {
+    'name': 'clang_format_mac',
+    'pattern': '.',
+    'action': [
+      'download_from_google_storage',
+      '--platform=^darwin$',
+      '--no_resume',
+      '--no_auth',
+      '--bucket=chromium-clang-format',
+      '--output=buildtools/mac/clang-format',
+      '--sha1_file',
+      'buildtools/mac/clang-format.sha1',
+    ],
+  },
+  {
+    'name': 'clang_format_win',
+    'pattern': '.',
+    'action': [
+      'download_from_google_storage',
+      '--platform=^win32$',
+      '--no_resume',
+      '--no_auth',
+      '--bucket=chromium-clang-format',
+      '--output=buildtools/win/clang-format.exe',
+      '--sha1_file',
+      'buildtools/win/clang-format.exe.sha1',
+    ],
+  },
+  {
     'name': 'gyp',
     'pattern': '\.gypi?$',
     'action': ['python', 'crashpad/build/gyp_crashpad.py'],
   },
 ]