Change clang_format.py to search for clang-format in buildtools

gclient_utils.py

 # 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.
 
 """Generic utils."""
 
 import codecs
 import cStringIO
 import datetime
 import logging
@@ skipping 637 matching lines @@
   elif sys.platform == 'darwin':
     return 'mac'
   raise Error('Unknown platform: ' + sys.platform)
 
 
 def GetBuildtoolsPath():
   """Returns the full path to the buildtools directory.
   This is based on the root of the checkout containing the current directory."""
   gclient_root = FindGclientRoot(os.getcwd())
   if not gclient_root:
+    # Some projects might not use .gclient. Try to see whether we're in a git
+    # checkout.
+    top_dir = [os.getcwd()]
+    def filter_fn(line):
+      top_dir[0] = os.path.normpath(line.rstrip('\n'))
+    try:
+      CheckCallAndFilter(["git", "rev-parse", "--show-toplevel"],
+                         print_stdout=False, filter_fn=filter_fn)
+    except Exception:
+      pass
+    top_dir = top_dir[0]
+    if os.path.exists(os.path.join(top_dir, 'buildtools')):
+      return os.path.join(top_dir, 'buildtools')
     return None
   return os.path.join(gclient_root, 'src', 'buildtools')
 
 
 def GetBuildtoolsPlatformBinaryPath():
   """Returns the full path to the binary directory for the current platform."""
   # Mac and Windows just have one directory, Linux has two according to whether
   # it's 32 or 64 bits.
   buildtools_path = GetBuildtoolsPath()
   if not buildtools_path:
@@ skipping 446 matching lines @@
 def DefaultIndexPackConfig(url=''):
   """Return reasonable default values for configuring git-index-pack.
 
   Experiments suggest that higher values for pack.threads don't improve
   performance."""
   cache_limit = DefaultDeltaBaseCacheLimit()
   result = ['-c', 'core.deltaBaseCacheLimit=%s' % cache_limit]
   if url in THREADED_INDEX_PACK_BLACKLIST:
     result.extend(['-c', 'pack.threads=1'])
   return result