Move base64url.* to CryptAuth component.

components/proximity_auth/base64url.cc

-// Copyright 2014 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.
-
-#include "components/proximity_auth/base64url.h"
-
-#include "base/base64.h"
-#include "base/strings/string_util.h"
-
-namespace proximity_auth {
-
-void Base64UrlEncode(const std::string& decoded_input,
-                     std::string* encoded_output) {
-  base::Base64Encode(decoded_input, encoded_output);
-  base::ReplaceChars(*encoded_output, "+", "-", encoded_output);
-  base::ReplaceChars(*encoded_output, "/", "_", encoded_output);
-}
-
-bool Base64UrlDecode(const std::string& encoded_input,
-                     std::string* decoded_output) {
-  std::string adjusted_encoded_input = encoded_input;
-  base::ReplaceChars(adjusted_encoded_input, "-", "+", &adjusted_encoded_input);
-  base::ReplaceChars(adjusted_encoded_input, "_", "/", &adjusted_encoded_input);
-
-  return base::Base64Decode(adjusted_encoded_input, decoded_output);
-}
-
-}  // namespace proximity_auth