Re-enable the grit hook, and make it more solid in case of failures....

build/win/clobber_generated_headers.py

 #!/usr/bin/python
 # Copyright (c) 2009 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 helps workaround IncrediBuild problem on Windows.
 # See http://crbug.com/17706.
 
 import os
 import sys
 
 _SRC_PATH = os.path.join(os.path.dirname(__file__), '..', '..')
 
 sys.path.append(os.path.join(_SRC_PATH, 'tools', 'grit'))
+import grit.exception
 import grit.grd_reader
 
 # We need to apply the workaround only on Windows.
 if os.name != 'nt':
   sys.exit(0)
 
 def total_split(path):
   components = []
   while path:
     head, tail = os.path.split(path)
     if not tail:
       break
     components.append(tail)
     path = head
   return list(reversed(components))
 
 for path in sys.argv[1:]:
   path = os.path.join('src', path)
   path_components = total_split(path)
-  root = grit.grd_reader.Parse(path)
+  try:
+    root = grit.grd_reader.Parse(path)
+  except grit.exception.Base, exc:
+    # This hook exploded badly a few times on the buildbot with exception
+    # at this point. Do not exit with an error, just print more information
+    # for debugging.
+    # TODO(phajdan.jr): Make exception fatal when the root cause is fixed.
+    print 'Unexpected GRIT exception while processing ' + path
+    print exc
+    continue
   output_files = [node.GetOutputFilename() for node in root.GetOutputFiles()]
   output_headers = [file for file in output_files if file.endswith('.h')]
   for build_type in ('Debug', 'Release'):
     build_path = os.path.join(_SRC_PATH, 'chrome', build_type)
 
     # We guess target file output based on path of the grd file (the first
     # path component after 'src').
     intermediate_path = os.path.join(build_path, 'obj',
                                      'global_intermediate', path_components[1])
 
     for header in output_headers:
       full_path = os.path.join(intermediate_path, header)
       try:
         os.remove(full_path)
         print 'Clobbered ' + full_path
       except OSError:
         print 'Could not remove ' + full_path + '. Continuing.'