Add a snapshot for docgen and use it in the build

tools/create_sdk.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012, 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.
 #
 # A script which will be invoked from gyp to create an SDK.
 #
 # Usage: create_sdk.py sdk_directory
 #
@@ skipping 87 matching lines @@
   file_extension = ''
   if HOST_OS == 'win32':
     file_extension = '.bat'
 
   src = src_file + file_extension
   dest = join(dest_dir, basename(src_file) + file_extension)
   Copy(src, dest)
 
 
 def CopyDartScripts(home, sdk_root):
-  for executable in ['dart2js', 'dartanalyzer', 'dartdoc', 'pub']:
+  for executable in ['dart2js', 'dartanalyzer', 'dartdoc', 'docgen', 'pub']:

[ricow1, 2014/01/21 00:52:16]

pull out dartdoc?

     CopyShellScript(os.path.join(home, 'sdk', 'bin', executable),
                     os.path.join(sdk_root, 'bin'))
 
 
 def CopySnapshots(snapshots, sdk_root):
   for snapshot in ['dart2js', 'utils_wrapper', 'pub']:
     snapshot += '.dart.snapshot'
     copyfile(join(snapshots, snapshot),
              join(sdk_root, 'bin', 'snapshots', snapshot))
 
@@ skipping 134 matching lines @@
     with open(os.path.join(SDK_tmp, 'revision'), 'w') as f:
       f.write(revision + '\n')
       f.close()
 
   Copy(join(HOME, 'README.dart-sdk'), join(SDK_tmp, 'README'))
 
   move(SDK_tmp, SDK)
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))