[mb] Add mb config

This adds a minimal mb config to switch the v8 staging bot
to mb. External mb documentation:
https://chromium.googlesource.com/chromium/src/tools/mb/+/HEAD/docs/user_guide.md

After this is tested on the staging bot, mb configs for the
remaining bots will be provided and all bots will be
systematically switched.

BUG=chromium:616035
NOTRY=true

Review-Url: https://codereview.chromium.org/2024893002
Cr-Commit-Position: refs/heads/master@{#36847}

.gitignore

@@ -72,6 +72,7 @@ shell_g
 /tools/luci-go/linux64/isolate
 /tools/luci-go/mac64/isolate
 /tools/luci-go/win64/isolate.exe
+/tools/mb
 /tools/oom_dump/oom_dump
 /tools/oom_dump/oom_dump.o
 /tools/swarming_client

DEPS

@@ -17,6 +17,8 @@ deps = {
     Var("git_url") + "/chromium/buildtools.git" + "@" + "099f1da55bfe8caa12266371a7eb983698fb1d87",
   "v8/base/trace_event/common":
     Var("git_url") + "/chromium/src/base/trace_event/common.git" + "@" + "54b8455be9505c2cb0cf5c26bb86739c236471aa",
+  "v8/tools/mb":
+    Var('git_url') + '/chromium/src/tools/mb.git' + '@' + "66482e6d056affa96f6dec4ff166f52f748a0c00",
   "v8/tools/swarming_client":
     Var('git_url') + '/external/swarming.client.git' + '@' + "df6e95e7669883c8fe9ef956c69a544154701a49",
   "v8/testing/gtest":

infra/mb/mb_config.pyl

+# Copyright 2016 The V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  # This is a map of buildbot master names -> buildbot builder names ->
+  # config names (where each config name is a key in the 'configs' dict,
+  # below). MB uses this dict to look up which config to use for a given bot.
+  'masters': {
+    'client.v8': {
+      'V8 Linux - swarming staging': 'gn_swarming_release',
+    },
+  },
+
+  'configs': {
+    'gyp_swarming_release': [
+      'release_bot', 'swarming_bot', 'gyp'],
+    'gn_swarming_release': [
+      'release_bot', 'swarming_bot', 'gn'],
+  },
+
+  'mixins': {
+    'debug': {
+      'gn_args': 'is_debug=true',
+    },
+
+    'debug_bot': {
+      'mixins': ['debug', 'static', 'goma'],
+    },
+
+    'gn': {'type': 'gn'},
+
+    'goma': {
+      # The MB code will properly escape goma_dir if necessary in the GYP
+      # code path; the GN code path needs no escaping.
+      'gn_args': 'use_goma=true',
+      'gyp_defines': 'use_goma=1',
+    },
+
+    'gyp': {'type': 'gyp'},
+
+    # TODO(machenbach): Remove the following two configs, once the v8 default
+    # has changed.
+    'no_sysroot': {
+      'gn_args': 'use_sysroot=false',
+    },
+
+    'no_icu_data_file': {
+      'gn_args': 'icu_use_data_file=false',
+    },
+
+    'release': {
+      'gn_args': 'is_debug=false',
+    },
+
+    'release_bot': {
+      'mixins': ['release', 'static', 'goma'],
+    },
+
+    'shared': {
+      'gn_args': 'is_component_build=true',
+      'gyp_defines': 'component=shared_library',
+    },
+
+    'static': {
+      'gn_args': 'is_component_build=false',
+      'gyp_defines': 'component=static_library',
+    },
+
+    'swarming': {
+      'gn_args': 'v8_test_isolation_mode="prepare"',
+      'gyp_defines': 'test_isolation_mode=prepare',
+    },
+
+    'swarming_bot': {
+      'mixins': ['swarming', 'no_sysroot', 'no_icu_data_file'],
+    },
+  },
+}