Remove XP and Vista bots from chromium.win and chromium.webkit waterfalls.

masters/master.tryserver.chromium.win/slaves.cfg

 # -*- python -*-
 # ex: set syntax=python:
 # Copyright 2014 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.
 
 def distribute_slaves(slave_numbers, builders, os_ver, pool=None, gce=False):
   hostname_format = 'vm%d-m4' if not gce else 'slave%d-c4'
   preference = slave_numbers >= builders
   return [
@@ skipping 26 matching lines @@
 
   optional_slaves = [177, 187, 192]
   optional_builders = [
       'win_archive',
       'win_chromium_compile_rel_ng',
       'win_chromium_dbg_ng',
       'win_chromium_gn_x64_dbg',
       'win_chromium_gn_x64_rel',
       'win_chromium_syzyasan_rel',
       'win_chromium_variable',
-      'win_chromium_vista_rel_ng',
-      'win_chromium_xp_rel_ng',
       'win_deterministic',
       'win_nacl_sdk',
       'win_nacl_sdk_build',
       'win_optional_gpu_tests_rel',
   ]
   optional_pool = distribute_slaves(
       optional_slaves, optional_builders, 'win7', 'win_optional')
 
   win8_slaves = ([115, 168, 722, 798, 799] + range(384, 399) +
       range(408, 422) + range(468, 495) +
@@ skipping 53 matching lines @@
       cq_pool +
       optional_pool +
       win8_pool +
       win10_pool +
       win_pgo_pool +
       experimental_pool +
       clang_win_pool)
 
 
 slaves = windows()