[tools] opt out of metrics when fetching deps for node

R=machenbach@chromium.org

Change-Id: Ia50f6e637aec58e9c1bdd726c84b296fd71d7cbb
Reviewed-on: https://chromium-review.googlesource.com/1142767Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54571}

tools/node/node_common.py

@@ -27,6 +27,10 @@ def EnsureDepotTools(v8_path, fetch_if_not_exist):
       subprocess.check_call("git clone {} {}".format(
           pipes.quote(DEPOT_TOOLS_URL),
           pipes.quote(depot_tools)), shell=True)
+      # Using check_output to hide warning messages.
+      subprocess.check_output(
+          [sys.executable, gclient_path, "metrics", "--opt-out"],
+          cwd=depot_tools)
       return depot_tools
     return None
   depot_tools = _Get(v8_path)