Upload/Download dart_snapshotter

mojo/dart/dart_snapshotter/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-executable("dart_snapshotter") {
-  sources = [
-    "main.cc",
-    "vm.cc",
-    "vm.h",
-  ]
+import("//mojo/public/mojo.gni")
 
-  deps = [
-    "//base",
-    "//build/config/sanitizers:deps",
-    "//dart/runtime/vm:libdart_platform",
-    "//dart/runtime:libdart",
-    "//mojo/common",
-    "//mojo/dart/embedder:dart_snapshot_cc",
-    "//mojo/edk/system",
-    "//mojo/environment:chromium",
-    "//mojo/public/cpp/system",
-    "//mojo/public/cpp/utility",
-    "//mojo/public/interfaces/application",
-    "//third_party/zlib",
-    "//tonic",
-  ]
+if (!mojo_use_prebuilt_dart_snapshotter) {
+  executable("dart_snapshotter") {
+    sources = [
+      "main.cc",
+      "vm.cc",
+      "vm.h",
+    ]
+
+    deps = [
+      "//base",
+      "//build/config/sanitizers:deps",
+      "//dart/runtime/vm:libdart_platform",
+      "//dart/runtime:libdart",
+      "//mojo/common",
+      "//mojo/dart/embedder:dart_snapshot_cc",
+      "//mojo/edk/system",
+      "//mojo/environment:chromium",
+      "//mojo/public/cpp/system",
+      "//mojo/public/cpp/utility",
+      "//mojo/public/interfaces/application",
+      "//third_party/zlib",
+      "//tonic",
+    ]
+  }
 }