Fix UB in SkDivBits

tools/dm_flags.py

 #
 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 #!/usr/bin/env python
 
 usage = '''
@@ skipping 151 matching lines @@
     blacklist.extend('_ image _ interlaced3.png'.split(' '))
 
   if blacklist:
     args.append('--blacklist')
     args.extend(blacklist)
 
   match = []
   if 'Valgrind' in bot: # skia:3021
     match.append('~Threaded')
 
-  # skia:3562
-  if ('TSAN' in bot or
-      'Test-Mac10.8-Clang-MacMini4.1-CPU-SSE4-x86_64-Release' in bot):
-    match.append('~Math')
-
   if 'GalaxyS3' in bot:  # skia:1699
     match.append('~WritePixels')
 
   # skia:3249: these images flakily don't decode on Android.
   if 'Android' in bot:
     match.append('~tabl_mozilla_0')
     match.append('~desk_yahoonews_0')
 
   if 'NexusPlayer' in bot:
     match.append('~ResourceCache')
@@ skipping 54 matching lines @@
   if len(sys.argv) == 2 and sys.argv[1] == 'test':
     self_test()
     sys.exit(0)
 
   if len(sys.argv) != 3:
     print usage
     sys.exit(1)
 
   with open(sys.argv[1], 'w') as out:
     json.dump(get_args(sys.argv[2]), out)