dart2js has its own snapshot.

dart/dart.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'most',
       'type': 'none',
       'dependencies': [
@@ skipping 50 matching lines @@
         'compiler',
       ],
       'actions': [
         {
           'action_name': 'create_sdk_py',
           'inputs': [
             '<!@(["python", "tools/list_files.py", "\\.dart$", "sdk/lib"])',
             '<!@(["python", "tools/list_files.py", "", "sdk/bin"])',
             'tools/create_sdk.py',
             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
+            '<(SHARED_INTERMEDIATE_DIR)/dart2js.dart.snapshot',
             '<(SHARED_INTERMEDIATE_DIR)/utils_wrapper.dart.snapshot',
             '<(SHARED_INTERMEDIATE_DIR)/pub.dart.snapshot',
             '<(PRODUCT_DIR)/analyzer/bin/dart_analyzer',
             '<(PRODUCT_DIR)/dartanalyzer/dartanalyzer.jar',
           ],
           'outputs': [
             '<(PRODUCT_DIR)/dart-sdk/README',
           ],
           'action': [
             'python',
@@ skipping 140 matching lines @@
     },
     {
       'target_name': 'packages',
       'type': 'none',
       'dependencies': [
         'pkg/pkg.gyp:pkg_packages',
       ],
     },
   ],
 }