Start archiving metrics_metadata with builds.

BUILD.gn

 # 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 is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 64 matching lines @@
 
   deps = [
     ":gn_visibility",
     "//base:base_unittests",
     "//chrome/installer",
     "//components:components_unittests",
     "//net:net_unittests",
     "//skia:skia_unittests",
     "//sql:sql_unittests",
     "//tools/ipc_fuzzer:ipc_fuzzer_all",
+    "//tools/metrics:metrics_metadata",
     "//ui/base:ui_base_unittests",
     "//ui/gfx:gfx_unittests",
     "//url:url_unittests",
   ]
 
   if (!is_android && !is_chromecast) {
     deps += [
       "//crypto:crypto_unittests",
       "//google_apis/gcm:gcm_unit_tests",
     ]
@@ skipping 998 matching lines @@
   assert(target_name != "")  # Mark as used.
   sources = invoker.actual_sources
   assert(
       sources == invoker.actual_sources,
       "Do not use a platform name in your output directory (found \"$root_build_dir\"). http://crbug.com/548283")
 }
 
 assert_valid_out_dir("_unused") {
   actual_sources = [ "$root_build_dir/foo" ]
 }