Polymer: Update find_unused_elements.py

third_party/polymer/v1_0/find_unused_elements.py

Index: third_party/polymer/v1_0/find_unused_elements.py
diff --git a/third_party/polymer/v1_0/find_unused_elements.py b/third_party/polymer/v1_0/find_unused_elements.py
index 5dbacdbdcbcec33a1c587eb987f182fc234e3025..1097d800604dfff4fd49762c7c89019cd18e9b10 100644
--- a/third_party/polymer/v1_0/find_unused_elements.py
+++ b/third_party/polymer/v1_0/find_unused_elements.py
@@ -11,7 +11,13 @@ to check if other elements have become unused.
 import os
 import re
 import subprocess
+import sys
 
+_HERE_PATH = os.path.dirname(__file__)
+_SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..'))
+sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'node'))
+import node
+import node_modules
 
 class UnusedElementsDetector(object):
   """Finds unused Polymer elements."""
@@ -58,8 +64,7 @@ class UnusedElementsDetector(object):
     text = re.sub('<if .*?>', '', text, flags=re.IGNORECASE)
     text = re.sub('</if>', '', text, flags=re.IGNORECASE)
 
-    proc = subprocess.Popen(['uglifyjs', filename], stdout=subprocess.PIPE)
-    return proc.stdout.read()
+    return node.RunNode([node_modules.PathToUglify(), filename])
 
   @staticmethod
   def __StripComments(filename):
@@ -133,11 +138,6 @@ class UnusedElementsDetector(object):
           if not filename.endswith('.html') and not filename.endswith('.js'):
             continue
 
-          # Skip generated files that may include the element source.
-          if filename in ('crisper.js', 'vulcanized.html',
-                          'app.crisper.js', 'app.vulcanized.html'):
-            continue
-
           with open(os.path.join(dirpath, filename)) as f:
             text = f.read()
           if not re.search('/%s/' % element_dir, text):