Remove now unused Balsa code.

net/tools/balsa/string_piece_utils.h

-// Copyright 2013 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.
-
-#ifndef NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_
-#define NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_
-
-#include <stddef.h>
-
-#include "base/strings/string_piece.h"
-#include "base/strings/string_util.h"
-
-namespace net {
-
-struct StringPieceCaseHash {
-  size_t operator()(const base::StringPiece& sp) const {
-    // based on __stl_string_hash in http://www.sgi.com/tech/stl/string
-    size_t hash_val = 0;
-    for (base::StringPiece::const_iterator it = sp.begin();
-         it != sp.end(); ++it) {
-      hash_val = 5 * hash_val + base::ToLowerASCII(*it);
-    }
-    return hash_val;
-  }
-};
-
-struct StringPieceCaseEqual {
-  bool operator()(const base::StringPiece& piece1,
-                  const base::StringPiece& piece2) const {
-    return base::EqualsCaseInsensitiveASCII(piece1, piece2);
-  }
-};
-
-}  // namespace net
-
-#endif  // NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_
-