Moved the FakeDownloadItem to content/public/test.

chrome/browser/ntp_snippets/BUILD.gn

Index: chrome/browser/ntp_snippets/BUILD.gn
diff --git a/chrome/browser/ntp_snippets/BUILD.gn b/chrome/browser/ntp_snippets/BUILD.gn
deleted file mode 100644
index 474a6f8fb15fd6ee5acdf9737bf2577ee4037588..0000000000000000000000000000000000000000
--- a/chrome/browser/ntp_snippets/BUILD.gn
+++ /dev/null
@@ -1,13 +0,0 @@
-# Copyright 2016 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("test_support") {
-  testonly = true
-  sources = [
-    "fake_download_item.cc",
-    "fake_download_item.h",
-  ]
-
-  deps = []
-}