[MD WebUI] Polymer-CSS-Build across all bundles.

third_party/node/node.py

 #!/usr/bin/env python
 # Copyright 2017 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.
 
 from os import path as os_path
 import platform
+import subprocess
+import sys
 
 
 def GetBinaryPath():
   return os_path.join(os_path.dirname(__file__), *{
     'Darwin': ('mac', 'node-darwin-x64', 'bin', 'node'),
     'Linux': ('linux', 'node-linux-x64', 'bin', 'node'),
     'Windows': ('win', 'node.exe'),
   }[platform.system()])
+
+
+def RunNode(cmd_parts, stdout=None):
+  cmd = " ".join([GetBinaryPath()] + cmd_parts)
+  process = subprocess.Popen(
+      cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
+  stdout, stderr = process.communicate()
+
+  if stderr:
+    print >> sys.stderr, '%s failed: %s' % (cmd, stderr)
+    raise
+
+  return stdout