Remove references to GClientKeywords.FromImpl from roll scripts

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index de0e49d65750255fb06707223f5908944d124136..8a81bb0babc1d3961b1dfea2fa5894d6ce306bad 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -1140,12 +1140,6 @@ def _ExtractAddRulesFromParsedDeps(parsed_deps):
 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):
@@ -1160,8 +1154,6 @@ def _ParseDeps(contents):
 
   local_scope = {}
   global_scope = {
-      'File': FileImpl,
-      'From': FromImpl,
       'Var': _VarImpl(local_scope).Lookup,
   }
   exec contents in global_scope, local_scope