Move files from the secondary GN directory to build.

tools/gn/secondary/build/util/BUILD.gn

Index: tools/gn/secondary/build/util/BUILD.gn
diff --git a/tools/gn/secondary/build/util/BUILD.gn b/tools/gn/secondary/build/util/BUILD.gn
deleted file mode 100644
index d43cc4907aa20a0543501fa3c743c0eb15d35f7f..0000000000000000000000000000000000000000
--- a/tools/gn/secondary/build/util/BUILD.gn
+++ /dev/null
@@ -1,35 +0,0 @@
-# Copyright (c) 2013 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.
-
-# This target generates a "last_change.h" header file in the generated files
-# directory that contains a define of the last revision of the source tree
-# of the form:
-#  #define LAST_CHANGE "123456"
-#
-# The version is a string rather than an integer for extra flexibility (for
-# example, we may require git hashes in the future).
-#
-# All you nede to do is depend on this target, and then from your source code:
-#  #include "build/util/last_change.h"
-custom("last_change") {
-  script = "//build/util/lastchange.py"
-
-  # This script must be run before targets depending on us.
-  hard_dep = true
-
-  # Rerun the script any time this file changes.
-  source_prereqs = [ "//build/util/LASTCHANGE" ]
-
-  output_header = "$target_gen_dir/last_change.h"
-  outputs = [ output_header ]
-
-  build_relative_src = rebase_path("//", ".", root_build_dir)
-  build_relative_outputs = rebase_path(output_header, ".", root_build_dir)
-
-  args = [
-    "--source-dir=$build_relative_src",
-    "--header=$build_relative_outputs",
-    "--version-macro=LAST_CHANGE",
-  ]
-}