Add `front_end` sources to the SDK (#27857).

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 36 matching lines @@
 # ......_internal/
 #.........spec.sum
 #.........strong.sum
 #.........dev_compiler/
 # ......analysis_server/
 # ......analyzer/
 # ......async/
 # ......collection/
 # ......convert/
 # ......core/
+# ......front_end/
 # ......html/
 # ......internal/
 # ......io/
 # ......isolate/
 # ......js/
 # ......js_util/
 # ......math/
 # ......mirrors/
 # ......typed_data/
 # ......api_readme.md
@@ skipping 71 matching lines @@
 
 
 def CopySnapshots(snapshots, sdk_root):
   for snapshot in ['analysis_server', 'dart2js', 'dartanalyzer', 'dartfmt',
                    'utils_wrapper', 'pub', 'dartdoc', 'dartdevc']:
     snapshot += '.dart.snapshot'
     copyfile(join(snapshots, snapshot),
              join(sdk_root, 'bin', 'snapshots', snapshot))
 
 def CopyAnalyzerSources(home, lib_dir):
-  for library in ['analyzer', 'analysis_server']:
+  for library in ['analyzer', 'analysis_server', 'front_end']:
     copytree(join(home, 'pkg', library), join(lib_dir, library),
              ignore=ignore_patterns('*.svn', 'doc', '*.py', '*.gypi', '*.sh',
                                     '.gitignore', 'packages'))
 
 def CopyDartdocResources(home, sdk_root):
   RESOURCE_DIR = join(sdk_root, 'bin', 'snapshots', 'resources')
   DARTDOC = join(RESOURCE_DIR, 'dartdoc')
 
   copytree(join(home, 'third_party', 'pkg', 'dartdoc', 'lib', 'templates'),
            join(DARTDOC, 'templates'))
@@ skipping 168 matching lines @@
       f.close()
 
   Copy(join(HOME, 'README.dart-sdk'), join(SDK_tmp, 'README'))
   Copy(join(HOME, 'LICENSE'), join(SDK_tmp, 'LICENSE'))
   Copy(join(HOME, 'sdk', 'api_readme.md'), join(SDK_tmp, 'lib', 'api_readme.md'))
 
   move(SDK_tmp, SDK)
 
 if __name__ == '__main__':
   sys.exit(Main())