Don't clobber symlinks to build directories

build/clobber.py

 #!/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.
 
 """This script provides methods for clobbering build directories."""
 
 import argparse
 import os
 import shutil
@@ skipping 19 matching lines @@
       line = f.readline()
       if len(line) == 0:
         return ''  # Unexpected EOF.
       result += line
       if line[0] == '\n':
         num_blank_lines = num_blank_lines + 1
   return result
 
 
 def delete_dir(build_dir):
+  if os.path.islink(build_dir):
+    return
   # For unknown reasons (anti-virus?) rmtree of Chromium build directories
   # often fails on Windows.
   if sys.platform.startswith('win'):
     subprocess.check_call(['rmdir', '/s', '/q', build_dir], shell=True)
   else:
     shutil.rmtree(build_dir)
 
 
 def delete_build_dir(build_dir):
   # GN writes a build.ninja.d file. Note that not all GN builds have args.gn.
@@ skipping 71 matching lines @@
 def main():
   parser = argparse.ArgumentParser()
   parser.add_argument('out_dir', help='The output directory to clobber')
   args = parser.parse_args()
   clobber(args.out_dir)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())