Revert of Update re2

third_party/re2/re2/testing/null_walker.cc

 // Copyright 2009 The RE2 Authors.  All Rights Reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "util/test.h"
 #include "re2/regexp.h"
 #include "re2/walker-inl.h"
 
 namespace re2 {
 
 // Null walker.  For benchmarking the walker itself.
 
 class NullWalker : public Regexp::Walker<bool> {
  public:
   NullWalker() { }
   bool PostVisit(Regexp* re, bool parent_arg, bool pre_arg,
                  bool* child_args, int nchild_args);
 
   bool ShortVisit(Regexp* re, bool a) {
     // Should never be called: we use Walk not WalkExponential.
     LOG(DFATAL) << "NullWalker::ShortVisit called";
     return a;
   }
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(NullWalker);
+  DISALLOW_EVIL_CONSTRUCTORS(NullWalker);
 };
 
 // Called after visiting re's children.  child_args contains the return
 // value from each of the children's PostVisits (i.e., whether each child
 // can match an empty string).  Returns whether this clause can match an
 // empty string.
 bool NullWalker::PostVisit(Regexp* re, bool parent_arg, bool pre_arg,
                                   bool* child_args, int nchild_args) {
   return false;
 }
 
 // Returns whether re can match an empty string.
 void Regexp::NullWalk() {
   NullWalker w;
   w.Walk(this, false);
 }
 
 }  // namespace re2