Added helper scripts for modifying polymer_resources.grdp.

tools/polymer/polymer_grdp_to_txt.py

Index: tools/polymer/polymer_grdp_to_txt.py
diff --git a/tools/polymer/polymer_grdp_to_txt.py b/tools/polymer/polymer_grdp_to_txt.py
new file mode 100755
index 0000000000000000000000000000000000000000..f9c8735720cc981b8713e8dd2a7dc3402919362d
--- /dev/null
+++ b/tools/polymer/polymer_grdp_to_txt.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+# Copyright 2015 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 sys
+import xml.sax
+
+
+class PathsExtractor(xml.sax.ContentHandler):
+
+  def __init__(self):
+    self.paths = []
+
+  def startElement(self, name, attrs):
+    if name != 'structure':
+      return
+    path = attrs['file']
+    if path.startswith('../../../third_party/web-animations-js'):
+      return
+    prefix = '../../../third_party/polymer/components-chromium/'
+    if not path.startswith(prefix):
+      raise Exception("Unexpected path %s." % path)
+    self.paths.append(path[len(prefix):])
+
+
+def main(argv):
+  xml_handler = PathsExtractor()
+  xml.sax.parse(sys.argv[1], xml_handler)

[dzhioev (left Google), 2015/03/17 18:26:46]

Should be just "argv[1]". Fixed in the next patchset.

+  print '\n'.join(sorted(xml_handler.paths))
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))

[Dan Beam, 2015/03/17 16:37:53]

I don't think this is the way you're supposed to use sys.exit():
https://docs.python.org/2/library/sys.html#sys.exit

[dzhioev (left Google), 2015/03/17 18:26:46]

I don't see what is wrong.
main() can optionally return exit code. If it doesn't return anything, exit code
will be 0.

[Dan Beam, 2015/03/17 18:37:53]

i guess None is 0-ish, yeah, but there's nothing that would actually return 1.

this is similar to try/except when nothing can go wrong... what's the point? 
just messes with the reader.

[dzhioev (left Google), 2015/03/18 16:38:05]

Probably such construction is idiomatic in Python. There are hundreds of
"sys.exit(main(" in Chromium sources and often main() doesn't return anything.