dart2js has its own snapshot.

dart/utils/compiler/compiler.gyp

Index: dart/utils/compiler/compiler.gyp
diff --git a/dart/utils/compiler/compiler.gyp b/dart/utils/compiler/compiler.gyp
index e5eb4ab414b8f0b623468c7bad7dc3fb49f8e7f2..d1c1c8e8f09f02560ef28f65baaa60dda149628c 100644
--- a/dart/utils/compiler/compiler.gyp
+++ b/dart/utils/compiler/compiler.gyp
@@ -20,6 +20,29 @@
           'inputs': [
             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
             '../../sdk/lib/_internal/libraries.dart',
+            '<!@(["python", "../../tools/list_files.py", "\\.dart$",'
+            ' "../../sdk/lib/_internal/compiler", "../../runtime/lib"])',
+            '../../sdk/lib/_internal/libraries.dart',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/dart2js.dart.snapshot',
+          ],
+          'action': [
+            '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
+            # Note: we don't store the snapshot in the location where
+            # the dart2js script is looking for it.  The motivation
+            # for that is to support an incremental development model
+            # for dart2js compiler engineers.  However, we install the
+            # snapshot in the proper location when building the SDK.
+            '--snapshot=<(SHARED_INTERMEDIATE_DIR)/dart2js.dart.snapshot',
+            '../../sdk/lib/_internal/compiler/implementation/dart2js.dart',
+          ],
+        },
+        {
+          'action_name': 'generate_dartdoc_snapshot',
+          'inputs': [
+            '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
+            '../../sdk/lib/_internal/libraries.dart',
             '<!@(["python", "../../tools/list_files.py", "\\.dart$", "../../sdk/lib/_internal/compiler", "../../runtime/lib", "../../sdk/lib/_internal/dartdoc"])',
             'create_snapshot.dart',
             '<(SHARED_INTERMEDIATE_DIR)/packages.stamp',