Bump vpython pin ad60019cb66 -> aacec5af4d5.

The new version understands CIPD_PROTOCOL=v2 env var which will be used to verify
the new protocol works for everything before it becomes default.

R=iannucci@chromium.org, dpranke@chromium.org, bsheedy@chromium.org
BUG=801423

Change-Id: Ic169831f427d0d718c15dde8481d689e71776a68
Reviewed-on: https://chromium-review.googlesource.com/1115468Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570562}

chrome/test/vr/auto_bisect.py

@@ -359,10 +359,10 @@ def RunTestOnSwarming(args, unknown_args, output_dir):
     '${platform}:git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c',
 
     '.swarming_module:infra/tools/luci/vpython-native/'
-    '${platform}:git_revision:ad60019cb66a75b59991d43b95a43f68e3fff81b',
+    '${platform}:git_revision:aacec5af4d569cee51437a89425db0b3c3d39a0a',
 
     '.swarming_module:infra/tools/luci/vpython/'
-    '${platform}:git_revision:ad60019cb66a75b59991d43b95a43f68e3fff81b',
+    '${platform}:git_revision:aacec5af4d569cee51437a89425db0b3c3d39a0a',
   ]
   for package in cipd_packages:
     swarming_args.extend(['--cipd-package', package])

tools/mb/mb.py

@@ -385,9 +385,9 @@ class MetaBuildWrapper(object):
       ('infra/tools/luci/logdog/butler/${platform}',
        'git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c'),
       ('infra/tools/luci/vpython-native/${platform}',
-       'git_revision:ad60019cb66a75b59991d43b95a43f68e3fff81b'),
+       'git_revision:aacec5af4d569cee51437a89425db0b3c3d39a0a'),
       ('infra/tools/luci/vpython/${platform}',
-       'git_revision:ad60019cb66a75b59991d43b95a43f68e3fff81b'),
+       'git_revision:aacec5af4d569cee51437a89425db0b3c3d39a0a'),
     ]
     for pkg, vers in cipd_packages:
       cmd.append('--cipd-package=.swarming_module:%s:%s' % (pkg, vers))