Add GN build for some chrome common, chrome net, and resources targets.

chrome/common/metrics/proto/BUILD.gn

Index: chrome/common/metrics/proto/BUILD.gn
diff --git a/content/browser/speech/proto/BUILD.gn b/chrome/common/metrics/proto/BUILD.gn
similarity index 71%
copy from content/browser/speech/proto/BUILD.gn
copy to chrome/common/metrics/proto/BUILD.gn
index fb54fb25906c99068b08c8568925f85bd69cb7ba..f0ff74d504a4a627e33dbab3e2717a1addb49bde 100644
--- a/content/browser/speech/proto/BUILD.gn
+++ b/chrome/common/metrics/proto/BUILD.gn
@@ -1,11 +1,12 @@
-# Copyright 2014 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.
-
-import("//third_party/protobuf/proto_library.gni")
-
-proto_library("proto") {
-  sources = [
-    "google_streaming_api.proto",
-  ]
-}
+# Copyright 2014 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.
+
+import("//third_party/protobuf/proto_library.gni")
+
+# GYP version: chrome/chrome_common.gypi:metrics_proto
+proto_library("proto") {
+  sources = [
+    "chrome_experiments.proto",
+  }
+}