GN: get echo-headers sources via exec_script

gyp/find.py

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 '''
-find.py is a poor-man's emulation of `find $1 -name=$2` on Unix.
+find.py is a poor-man's emulation of `find -name=$1 $2` on Unix.
 
-Call python find.py <directory> <glob> to list all files matching glob under
+Call python find.py <glob> <directory>... to list all files matching glob under
 directory (recursively).  E.g.
-   $ python find.py ../tests/ '*.cpp'
-will print all .cpp files under ../tests/.
+   $ python find.py '*.cpp' ../tests/ ../bench/
+will print all .cpp files under ../tests/ and ../bench/.
 '''
 
 import fnmatch
 import os
 import sys
 
-for d, kids, files in os.walk(sys.argv[1]):
-  files.sort()
-  for f in files:
-    if fnmatch.fnmatch(f, sys.argv[2]):
-      print os.path.join(d, f).replace('\\', '/')  # Gyp wants Unix paths.
+for directory in sys.argv[2:]:
+  for d, kids, files in os.walk(directory):
+    files.sort()
+    for f in files:
+      if fnmatch.fnmatch(f, sys.argv[1]):
+        print os.path.join(d, f).replace('\\', '/')  # Gyp wants Unix paths.