Add support for build_limited subprojects in presubmit builder

scripts/slave/recipe_modules/gclient/config.py

 # Copyright 2013 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.
 
 import types
 
 from recipe_engine.config import config_item_context, ConfigGroup, BadConf
 from recipe_engine.config import ConfigList, Dict, Single, Static, Set, List
 
 from . import api as gclient_api
@@ skipping 390 matching lines @@
   build(c)
   c.got_revision_mapping['build'] = 'got_build_revision'
 
 @config_ctx(config_vars={'GIT_MODE': True})
 def build_limited(c):
   if not c.GIT_MODE:  # pragma: no cover
     raise BadConf('build_limited only supports git')
   s = c.solutions.add()
   s.name = 'build_limited'
   s.url = 'https://chrome-internal.googlesource.com/chrome/tools/build_limited'
+  # In order to run presubmit, we checkout the whole build_limited repository
+  # and build repository next to it. However, the patch in CQ needs to be
+  # applied to one of the subfolders of build_limited only and run_presubmit.py
+  # uses the patch to this directory (from gclient root) to find the property
+  # with checked out revision. Since all these subfolders are the part of a
+  # single repository, we map them to the same property here.
   c.got_revision_mapping['build_limited'] = 'got_revision'
+  c.got_revision_mapping['build_limited/scripts/slave'] = 'got_revision'
   # We do not use 'includes' here, because we want build_internal to be the
   # first solution in the list as run_presubmit computes upstream revision
   # from the first solution.
   build(c)
   c.got_revision_mapping['build'] = 'got_build_revision'
 
 @config_ctx(includes=['chromium', 'chrome_internal'])
 def perf(c):
   s = c.solutions[0]
   s.custom_vars['llvm_url'] = 'svn://svn-mirror.golo.chromium.org/llvm-project'
@@ skipping 88 matching lines @@
   soln.url = ('https://chromium.googlesource.com/external/github.com/'
               'catapult-project/catapult.git')
   c.got_revision_mapping['catapult'] = 'got_revision'
 
 @config_ctx(includes=['infra_internal'], config_vars={'GIT_MODE': True})
 def infradata_config_internal(c):
   soln = c.solutions.add()
   soln.name = 'infra-data-configs'
   soln.url = 'https://chrome-internal.googlesource.com/infradata/config.git'
   c.got_revision_mapping['infra-data-config'] = 'got_revision'