Move some component's GN build files to main tree.

tools/gn/secondary/components/onc/BUILD.gn

Index: tools/gn/secondary/components/onc/BUILD.gn
diff --git a/tools/gn/secondary/components/onc/BUILD.gn b/tools/gn/secondary/components/onc/BUILD.gn
deleted file mode 100644
index 2b3aa66ce1beb877322f0a5b09902713a2af0bb3..0000000000000000000000000000000000000000
--- a/tools/gn/secondary/components/onc/BUILD.gn
+++ /dev/null
@@ -1,17 +0,0 @@
-# Copyright 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.
-
-component("onc_component") {
-  sources = [
-    "onc_constants.cc",
-    "onc_constants.h",
-    "onc_export.h",
-  ]
-
-  defines = [ "ONC_IMPLEMENTATION" ]
-
-  deps = [
-    "//base",
-  ]
-}