Move 7zip dependency to cloud storage

DEPS

 # 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.
 
 vars = {
   # The dart_root is the root of our sdk checkout. This is normally
   # simply sdk, but if using special gclient specs it can be different.
   "dart_root": "sdk",
 
   # The svn location to pull out dependencies from
@@ skipping 11 matching lines @@
   # github repo until the mirror has been created, but please do file a bug
   # against infra to make that happen.
   "github_mirror":
       "https://chromium.googlesource.com/external/github.com/dart-lang/%s.git",
 
   "gyp_rev": "@6ee91ad8659871916f9aa840d42e1513befdf638",
   "co19_rev": "@3ed795ea02e022ef19c77cf1b6095b7c8f5584d0",
   "chromium_git": "https://chromium.googlesource.com",
 
   # Revisions of /third_party/* dependencies.
-  "7zip_rev" : "@19997",
   "args_tag": "@0.13.0",
   "async_tag": "@1.4.0",
   "barback_tag" : "@0.15.2+7",
   "boringssl_rev" : "@daeafc22c66ad48f6b32fc8d3362eb9ba31b774e",
   "charcode_tag": "@1.1.0",
   "chrome_rev" : "@19997",
   "clang_rev" : "@28450",
   "cli_util_tag" : "@0.0.1+2",
   "collection_rev": "@f6135e6350c63eb3f4dd12953b8d4363faff16fc",
   "convert_tag": "@1.0.0",
@@ skipping 91 matching lines @@
       Var("jinja2_rev"),
 
   Var("dart_root") + "/third_party/ply":
       Var("chromium_git") + "/chromium/src/third_party/ply.git" +
       Var("ply_rev"),
 
   Var("dart_root") + "/third_party/idl_parser":
       Var("chromium_git") + "/chromium/src/tools/idl_parser.git" +
       Var("idl_parser_rev"),
 
-  Var("dart_root") + "/third_party/7zip":
-     Var("third_party") + "/7zip" + Var("7zip_rev"),
   Var("dart_root") + "/third_party/firefox_jsshell":
       Var("third_party") + "/firefox_jsshell" + Var("firefox_jsshell_rev"),
   Var("dart_root") + "/third_party/gsutil":
       Var("third_party") + "/gsutil" + Var("gsutil_rev"),
   Var("dart_root") + "/third_party/pkg/petitparser":
       Var("third_party") + "/petitparser" + Var("petitparser_rev"),
   Var("dart_root") + "/third_party/WebCore":
       Var("third_party") + "/WebCore" + Var("WebCore_rev"),
 
   Var("dart_root") + "/third_party/dart-services":
@@ skipping 211 matching lines @@
       "download_from_google_storage",
       "--no_auth",
       "--no_resume",
       "--bucket",
       "dart-dependencies",
       "--platform=win32",
       "--directory",
       Var('dart_root') + "/third_party/drt_resources",
     ],
   },
+  {
+    "name": "7zip",
+    "pattern": ".",
+    "action": [
+      "download_from_google_storage",
+      "--no_auth",
+      "--no_resume",
+      "--bucket",
+      "dart-dependencies",
+      "--platform=win32",
+      "--extract",
+      "-s",
+      Var('dart_root') + "/third_party/7zip.tar.gz.sha1",
+    ],
+  },
 ]