Revert of Extract some stuff into PackageManager

mojo/package_manager/BUILD.gn

Index: mojo/package_manager/BUILD.gn
diff --git a/mojo/package_manager/BUILD.gn b/mojo/package_manager/BUILD.gn
deleted file mode 100644
index 913a36dac280104c8e2b3ee800c0f0fca143e697..0000000000000000000000000000000000000000
--- a/mojo/package_manager/BUILD.gn
+++ /dev/null
@@ -1,16 +0,0 @@
-# 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.
-
-source_set("package_manager") {
-  sources = [
-    "package_manager_impl.cc",
-    "package_manager_impl.h",
-  ]
-
-  deps = [
-    "//mojo/fetcher",
-    "//mojo/shell",
-    "//mojo/util:filename_util",
-  ]
-}