Remove gerrit-buildbucket-config command from MB.

The Gerrit plugin will now automatically populate the list of
tryservers from LUCI, meaning that we no longer need to manually
configure things and don't need to generate a config file from
the MB entries. Accordingly, this CL removes the
`gerrit-buildbucket-config` code from MB.

Bug: 813196
Change-Id: I1c4ba1099a11822c2c741eb21dc61e4f5a163369
Reviewed-on: https://chromium-review.googlesource.com/1053377
Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557416}

tools/mb/docs/user_guide.md

@@ -186,21 +186,6 @@ Builds and isolates a given (ninja) target like the `isolate` command does,
 and then takes all of the files in the isolate and writes them into a single
 zip file that can then easily be redistributed.
 
-### mb gerrit-buildbucket-config
-
-Generates a gerrit buildbucket configuration file and prints it to
-stdout. This file contains the list of trybots shown in gerrit's UI.
-
-The master copy of the buildbucket.config file lives
-in a separate branch of the chromium repository. Run `mb
-gerrit-buildbucket-config > buildbucket.config.new && git fetch origin
-refs/meta/config:refs/remotes/origin/meta/config && git checkout
--t -b meta_config origin/meta/config && mv buildbucket.config.new
-buildbucket.config` to update the file.
-
-Note that after committing, `git cl upload` will not work. Instead, use `git
-push origin HEAD:refs/for/refs/meta/config` to upload the CL for review.
-
 ## Isolates and Swarming
 
 `mb gen` is also responsible for generating the `.isolate` and

tools/mb/mb.py

@@ -54,7 +54,6 @@ class MetaBuildWrapper(object):
     self.sep = os.sep
     self.args = argparse.Namespace()
     self.configs = {}
-    self.luci_tryservers = {}
     self.masters = {}
     self.mixins = {}
 
@@ -222,14 +221,6 @@ class MetaBuildWrapper(object):
                       help='path to config file (default is %(default)s)')
     subp.set_defaults(func=self.CmdValidate)
 
-    subp = subps.add_parser('gerrit-buildbucket-config',
-                            help='Print buildbucket.config for gerrit '
-                            '(see MB user guide)')
-    subp.add_argument('-f', '--config-file', metavar='PATH',
-                      default=self.default_config,
-                      help='path to config file (default is %(default)s)')
-    subp.set_defaults(func=self.CmdBuildbucket)
-
     subp = subps.add_parser('zip',
                             help='generate a .zip containing the files needed '
                                  'for a given binary')
@@ -483,25 +474,6 @@ class MetaBuildWrapper(object):
             ('cpu', 'x86-64'),
             os_dim]
 
-  def CmdBuildbucket(self):
-    self.ReadConfigFile()
-
-    self.Print('# This file was generated using '
-               '"tools/mb/mb.py gerrit-buildbucket-config".')
-
-    for luci_tryserver in sorted(self.luci_tryservers):
-      self.Print('[bucket "luci.%s"]' % luci_tryserver)
-      for bot in sorted(self.luci_tryservers[luci_tryserver]):
-        self.Print('\tbuilder = %s' % bot)
-
-    for master in sorted(self.masters):
-      if master.startswith('tryserver.'):
-        self.Print('[bucket "master.%s"]' % master)
-        for bot in sorted(self.masters[master]):
-          self.Print('\tbuilder = %s' % bot)
-
-    return 0
-
   def CmdValidate(self, print_ok=True):
     errs = []
 
@@ -665,7 +637,6 @@ class MetaBuildWrapper(object):
                  (self.args.config_file, e))
 
     self.configs = contents['configs']
-    self.luci_tryservers = contents.get('luci_tryservers', {})
     self.masters = contents['masters']
     self.mixins = contents['mixins']
 

tools/mb/mb_config.pyl

@@ -2122,8 +2122,4 @@
       'gn_args': 'target_cpu="x86"',
     },
   },
-
-  'luci_tryservers': {
-    'chromium.try': [ 'linux_chromium_rel_ng' ],
-  },
 }

tools/mb/mb_unittest.py

@@ -190,10 +190,6 @@ TRYSERVER_CONFIG = """\
       'try_builder2': 'fake_config',
     },
   },
-  'luci_tryservers': {
-    'luci_tryserver1': ['luci_builder1'],
-    'luci_tryserver2': ['luci_builder2'],
-  },
   'configs': {},
   'mixins': {},
 }
@@ -631,22 +627,6 @@ class UnitTest(unittest.TestCase):
     mbw.files[mbw.default_config] = TEST_BAD_CONFIG
     self.check(['validate'], mbw=mbw, ret=1)
 
-  def test_buildbucket(self):
-    mbw = self.fake_mbw()
-    mbw.files[mbw.default_config] = TRYSERVER_CONFIG
-    self.check(['gerrit-buildbucket-config'], mbw=mbw,
-               ret=0,
-               out=('# This file was generated using '
-                    '"tools/mb/mb.py gerrit-buildbucket-config".\n'
-                    '[bucket "luci.luci_tryserver1"]\n'
-                    '\tbuilder = luci_builder1\n'
-                    '[bucket "luci.luci_tryserver2"]\n'
-                    '\tbuilder = luci_builder2\n'
-                    '[bucket "master.tryserver.chromium.linux"]\n'
-                    '\tbuilder = try_builder\n'
-                    '[bucket "master.tryserver.chromium.mac"]\n'
-                    '\tbuilder = try_builder2\n'))
-
   def test_build_command_unix(self):
     files = {
       '/fake_src/out/Default/toolchain.ninja': '',