Create a Dockerfile.base and ensure it is included in build tarballs.

blimp/BUILD.gn

 # Copyright 2015 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 # Convenience meta-target for all of Blimp's production & test code.
 group("blimp") {
@@ skipping 128 matching lines @@
   }
 
   # Builds and bundles the tests into a tarball that can be used to build a
   # Docker image.
   action("blimp_engine_env_tests_bundle") {
     testonly = true
     script = "//blimp/tools/create-bundle.py"
 
     # These form the arguments to the script.
     _rebased_out_dir = rebase_path(root_out_dir)
-    _rebased_dockerfile = rebase_path("//blimp/Dockerfile")
+    _rebased_dockerfile = rebase_path("//blimp/engine/testing/Dockerfile")
+    _rebased_dockerfile_base = rebase_path("//blimp/tools/Dockerfile.base")
     _bundle = "$root_out_dir/blimp_engine_env_tests_bundle.tar.gz"
 
     # Depending on this ensures that both the manifest is generated
     # and everything listed in the manifest has been built.
     deps = [
       ":generate_blimp_engine_env_tests_manifest",
     ]
 
     sources = [
       _blimp_engine_env_tests_manifest,
       _rebased_dockerfile,
+      _rebased_dockerfile_base,
     ]
     outputs = [
       _bundle,
     ]
     args = [
       "--build-dir",
       _rebased_out_dir,
       "--filelist",
       _rebased_dockerfile,
+      _rebased_dockerfile_base,
       "--manifest",
       _rebased_blimp_engine_env_tests_manifest,
       "--output",
       rebase_path(_bundle),
     ]
   }
 }