Allow checkdeps to function in the presence of File().

tools/checkdeps/checkdeps.py

 #!/usr/bin/python
 # Copyright (c) 2011 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.
 
 """Makes sure that files include headers from allowed directories.
 
 Checks DEPS files in the source tree for rules, and applies those rules to
 "#include" commands in source files. Any source file including something not
 permitted by the DEPS files will fail.
@@ skipping 228 matching lines @@
   if not (os.path.exists(os.path.join(dir_name, ".svn")) or
           (dir_name.lower() in GIT_SOURCE_DIRECTORY)):
     return (None, [])
 
   # Check the DEPS file in this directory.
   if VERBOSE:
     print "Applying rules from", dir_name
   def FromImpl(unused, unused2):
     pass  # NOP function so "From" doesn't fail.
 
+  def FileImpl(unused):
+    pass  # NOP function so "File" doesn't fail.
+
   class _VarImpl:
     def __init__(self, local_scope):
       self._local_scope = local_scope
 
     def Lookup(self, var_name):
       """Implements the Var syntax."""
       if var_name in self._local_scope.get("vars", {}):
         return self._local_scope["vars"][var_name]
       raise Error("Var is not defined: %s" % var_name)
 
   local_scope = {}
-  global_scope = {"From": FromImpl, "Var": _VarImpl(local_scope).Lookup}
+  global_scope = {
+      "File": FileImpl,
+      "From": FromImpl,
+      "Var": _VarImpl(local_scope).Lookup,
+      }
   deps_file = os.path.join(dir_name, "DEPS")
 
   if os.path.isfile(deps_file):
     execfile(deps_file, global_scope, local_scope)
   elif VERBOSE:
     print "  No deps file found in", dir_name
 
   # Even if a DEPS file does not exist we still invoke ApplyRules
   # to apply the implicit "allow" rule for the current directory
   deps = local_scope.get(DEPS_VAR_NAME, {})
@@ skipping 220 matching lines @@
 if '__main__' == __name__:
   option_parser = optparse.OptionParser()
   option_parser.add_option("", "--root", default="", dest="base_directory",
                            help='Specifies the repository root. This defaults '
                            'to "../../.." relative to the script file, which '
                            'will normally be the repository root.')
   option_parser.add_option("-v", "--verbose", action="store_true",
                            default=False, help="Print debug logging")
   options, args = option_parser.parse_args()
   main(options, args)