Add swarming_run_shim.py to run swarming tasks as annotated tasks.

scripts/slave/swarming/swarming_utils.py

 #!/usr/bin/env python
 # 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.
 
 """Code to find swarming_client."""
 
 import os
 import sys
 
 from common import find_depot_tools  # pylint: disable=W0611
 
 # From depot_tools/
 import subprocess2
 
 
 OS_MAPPING = {
     'darwin': 'Mac',
     'linux2': 'Linux',
     # TODO(maruel): This solves our immediate need of running all the swarming
     # tests by default on Win7 but this doesn't fix the usage on the CI for XP
     # and Vista.
     'win32': 'Windows-6.1',
 }
 
 
+# This should match build/scripts/master/factory/swarming_factory.py until the
+# code there is deleted.
+# The goal here is to take ~5m of actual test run per shard, e.g. the 'RunTest'
+# section in the logs, so that the trade-off of setup time overhead vs latency
+# is reasonable. The overhead is in the 15~90s range, with the vast majority
+# being downloading the executable files. While it can be lowered, it'll stay in
+# the "few seconds" range due to the sheer size of the executables to map.
+# Anything not listed defaults to 1 shard.
+TESTS_SHARDS = {
+    'browser_tests': 5,
+    'interactive_ui_tests': 3,
+    'sync_integration_tests': 4,
+    'unit_tests': 2,
+}
+
+
 def find_client(base_dir):
   """Returns the path to swarming_client if found.
 
   |base_dir| will be in general os.getcwd(), so the script is very dependent on
   CWD. CWD should be the base directory of the checkout. It has always been the
   case.
   """
   src_swarming_client = os.path.join(
       base_dir, 'src', 'tools', 'swarming_client')
   if os.path.isdir(src_swarming_client):
@@ skipping 12 matching lines @@
         [
           sys.executable,
           os.path.join(client, 'swarming.py'),
           '--version',
         ])
   except (subprocess2.CalledProcessError, OSError):
     return None
   version = tuple(map(int, version.split('.')))
   print('Detected swarming.py version %s' % '.'.join(map(str, version)))
   return version
+
+
+def build_to_priority(build_properties):
+  """Returns the Swarming task priority for the build.
+
+  Does this by determining the build type. Lower is higher priority.
+  """
+  url = build_properties.get('buildbotURL', '')
+  # TODO(maruel): It's a tad annoying to use the url as a signal here. It is
+  # just too easy to forget to update this list so find a way to specify the
+  # priority more clearly.
+  ci_masters = (
+      '/chromium/',
+      '/chromium.chrome/',
+      '/chromium.chromiumos/',
+      '/chromium.linux/',
+      '/chromium.mac/',
+      '/chromium.memory/',
+      '/chromium.win/',
+  )
+  try_masters = (
+      '/tryserver.chromium/',
+      '/tryserver.nacl/',
+  )
+
+  if url.endswith(ci_masters):
+    # Continuous integration master.
+    return 10
+
+  if url.endswith(try_masters):
+    requester = build_properties.get('requester')
+    if requester == 'commit-bot@chromium.org':
+      # Commit queue job.
+      return 30
+    # Normal try job.
+    return 50
+
+  # FYI builder or something else we do not know about. Run these at very low
+  # priority so if something is misconfigured above, we can catch it sooner.
+  return 200