Sort project headers in a case-sensitive way since PRESUBMIT enforces that

tools/sort-headers.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.
 
 """Given a filename as an argument, sort the #include/#imports in that file.
 
 Shows a diff and prompts for confirmation before doing the deed.
 Works great with tools/git/for-all-touched-files.py.
 """
@@ skipping 19 matching lines @@
   finally:
     termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
   print ch
   return ch in ('Y', 'y')
 
 
 def IncludeCompareKey(line):
   """Sorting comparator key used for comparing two #include lines.
   Returns the filename without the #include/#import prefix.
   """
-  line = line.lower()
   for prefix in ('#include ', '#import '):
     if line.startswith(prefix):
       line = line[len(prefix):]
       break
 
   # The win32 api has all sorts of implicit include order dependencies :-/
   # Give a few headers special sort keys that make sure they appear before all
   # other headers.
   if line.startswith('<windows.h>'):  # Must be before e.g. shellapi.h
     return '0'
   if line.startswith('<atlbase.h>'):  # Must be before atlapp.h.
     return '1' + line
   if line.startswith('<unknwn.h>'):  # Must be before e.g. intshcut.h
     return '1' + line
 
   # C++ system headers should come after C system headers.
   if line.startswith('<'):
     if line.find('.h>') != -1:
-      return '2' + line
+      return '2' + line.lower()
     else:
-      return '3' + line
+      return '3' + line.lower()
 
   return '4' + line
 
 
 def IsInclude(line):
   """Returns True if the line is an #include/#import line."""
   return line.startswith('#include ') or line.startswith('#import ')
 
 
 def SortHeader(infile, outfile):
@@ skipping 64 matching lines @@
   if len(filenames) < 1:
     parser.print_help()
     return 1
 
   for filename in filenames:
     DiffAndConfirm(filename, opts.should_confirm)
 
 
 if __name__ == '__main__':
   sys.exit(main())