Update from https://crrev.com/316786

tools/git/for-all-touched-files.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """
   Invokes the specified (quoted) command for all files modified
   between the current git branch and the specified branch or commit.
 
   The special token [[FILENAME]] (or whatever you choose using the -t
   flag) is replaced with each of the filenames of new or modified files.
 
   Deleted files are not included.  Neither are untracked files.
 
 Synopsis:
-  %prog [-b BRANCH] [-d] [-x EXTENSIONS|-c] [-t TOKEN] QUOTED_COMMAND
+  %prog [-b BRANCH] [-d] [-x EXTENSIONS|-c|-g] [-t TOKEN] QUOTED_COMMAND
 
 Examples:
   %prog -x gyp,gypi "tools/format_xml.py [[FILENAME]]"
   %prog -c "tools/sort-headers.py [[FILENAME]]"
+  %prog -g "tools/sort_sources.py [[FILENAME]]"
   %prog -t "~~BINGO~~" "echo I modified ~~BINGO~~"
 """
 
 import optparse
 import os
 import subprocess
 import sys
 
 
 # List of C++-like source file extensions.
 _CPP_EXTENSIONS = ('h', 'hh', 'hpp', 'c', 'cc', 'cpp', 'cxx', 'mm',)
+# List of build file extensions.
+_BUILD_EXTENSIONS = ('gyp', 'gypi', 'gn',)
 
 
 def GitShell(args, ignore_return=False):
   """A shell invocation suitable for communicating with git. Returns
   output as list of lines, raises exception on error.
   """
   job = subprocess.Popen(args,
                          shell=True,
                          stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)
@@ skipping 42 matching lines @@
 
 
 def main():
   parser = optparse.OptionParser(usage=__doc__)
   parser.add_option('-x', '--extensions', default='', dest='extensions',
                     help='Limits to files with given extensions '
                     '(comma-separated).')
   parser.add_option('-c', '--cpp', default=False, action='store_true',
                     dest='cpp_only',
                     help='Runs your command only on C++-like source files.')
+  # -g stands for GYP and GN.
+  parser.add_option('-g', '--build', default=False, action='store_true',
+                    dest='build_only',
+                    help='Runs your command only on build files.')
   parser.add_option('-t', '--token', default='[[FILENAME]]', dest='token',
                     help='Sets the token to be replaced for each file '
                     'in your command (default [[FILENAME]]).')
   parser.add_option('-b', '--branch', default='origin/master', dest='branch',
                     help='Sets what to diff to (default origin/master). Set '
                     'to empty to diff workspace against HEAD.')
   opts, args = parser.parse_args()
 
   if not args:
     parser.print_help()
     sys.exit(1)
 
+  if opts.cpp_only and opts.build_only:
+    parser.error("--cpp and --build are mutually exclusive")
+
   extensions = opts.extensions
   if opts.cpp_only:
     extensions = _CPP_EXTENSIONS
+  if opts.build_only:
+    extensions = _BUILD_EXTENSIONS
 
   ForAllTouchedFiles(opts.branch, extensions, opts.token, args[0])
 
 
 if __name__ == '__main__':
   main()