Remove references to GClientKeywords.FromImpl from roll scripts

PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Top-level presubmit script for Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
@@ skipping 1122 matching lines @@
     add_rules.update([
         rule[1:] for rule in rules
         if rule.startswith('+') or rule.startswith('!')
     ])
   return add_rules
 
 
 def _ParseDeps(contents):
   """Simple helper for parsing DEPS files."""
   # Stubs for handling special syntax in the root DEPS file.
-  def FromImpl(*_):
-    pass  # NOP function so "From" doesn't fail.
-
-  def FileImpl(_):
-    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."""
       try:
         return self._local_scope['vars'][var_name]
       except KeyError:
         raise Exception('Var is not defined: %s' % var_name)
 
   local_scope = {}
   global_scope = {
-      'File': FileImpl,
-      'From': FromImpl,
       'Var': _VarImpl(local_scope).Lookup,
   }
   exec contents in global_scope, local_scope
   return local_scope
 
 
 def _CalculateAddedDeps(os_path, old_contents, new_contents):
   """Helper method for _CheckAddedDepsHaveTargetApprovals. Returns
   a set of DEPS entries that we should look up.
 
@@ skipping 1297 matching lines @@
       output_api,
       json_url='http://chromium-status.appspot.com/current?format=json'))
 
   results.extend(
       input_api.canned_checks.CheckPatchFormatted(input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasBugField(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasDescription(
       input_api, output_api))
   return results