Add download of the stable SDK from gcloud to the gclient hooks in DEPS.

tools/create_tarball.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 #
 
 # Script to build a tarball of the Dart source.
 #
 # The tarball includes all the source needed to build Dart. This
@@ skipping 23 matching lines @@
 HOST_OS = utils.GuessOS()
 DART_DIR = abspath(join(__file__, '..', '..'))
 # Flags.
 verbose = False
 
 # Name of the dart directory when unpacking the tarball.
 versiondir = ''
 
 # Ignore Git/SVN files, checked-in binaries, backup files, etc..
 ignoredPaths = ['tools/testing/bin',
+                'tools/sdks',
                 'third_party/7zip', 'third_party/android_tools',
                 'third_party/clang', 'third_party/d8',
                 'third_party/firefox_jsshell']
 ignoredDirs = ['.svn', '.git']
 ignoredEndings = ['.mk', '.pyc', 'Makefile', '~']
 
 def BuildOptions():
   result = optparse.OptionParser()
   result.add_option("-v", "--verbose",
       help='Verbose output.',
@@ skipping 105 matching lines @@
   tar_filename = options.tar_filename
   if not tar_filename:
     tar_filename = join(DART_DIR,
                         utils.GetBuildDir(HOST_OS),
                         'dart-%s.tar.gz' % utils.GetVersion())
 
   CreateTarball(tar_filename)
 
 if __name__ == '__main__':
   sys.exit(Main())