Re-enable DepsCache using GOMA_DEPS_CACHE_FILE

scripts/slave/recipes/dart/dartium_android_builder.expected/dartium_builder_basic.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport os, sys\n\nbuild_path = sys.argv[1]\nif os.path.exists(build_path):\n  for (path, dir, files) in os.walk(build_path):\n    for cur_file in files:\n      if cur_file.endswith('index.lock'):\n        path_to_file = os.path.join(path, cur_file)\n        print 'deleting %s' % path_to_file\n        os.remove(path_to_file)\n",
       "[SLAVE_BUILD]"
     ],
     "name": "cleanup index.lock",
     "~followup_annotations": [
@@ skipping 240 matching lines @@
       "--src-dir",
       "[SLAVE_BUILD]/src",
       "--goma-cache-dir",
       "[GOMA_CACHE]",
       "--buildbot-buildername",
       "dartium-builder",
       "--buildbot-mastername",
       "chromium.testing.master",
       "--buildbot-slavename",
       "TestSlavename",
+      "--goma-deps-cache-file",
+      "dartium_builder.gomadeps",
       "--compiler",
       "goma",
       "--goma-jsonstatus",
       "/path/to/tmp/json",
       "--goma-service-account-json-file",
       "/creds/service_accounts/service-account-goma-client.json",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--",
       "content_shell_apk"
@@ skipping 17 matching lines @@
       "[SLAVE_BUILD]/src/out/Release"
     ],
     "name": "dartium_test"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]