Move base64url.* to CryptAuth component.

components/proximity_auth/cryptauth/base64url.h

 // 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.
 
-#ifndef COMPONENTS_PROXIMITY_BASE64URL_H
-#define COMPONENTS_PROXIMITY_BASE64URL_H
+#ifndef COMPONENTS_PROXIMITY_AUTH_CRYPTAUTH_BASE64URL_H
+#define COMPONENTS_PROXIMITY_AUTH_CRYPTAUTH_BASE64URL_H
 
 #include <string>
 
 namespace proximity_auth {
 
 // An implmentation of the base64url encoding. Escapes the unsafe '+' and '/'
 // characters with the url-safe alternatives '-' and '_', respectively. For more
 // info, see the section on "Base 64 Encoding with URL and Filename Safe
 // Alphabet" in http://www.ietf.org/rfc/rfc4648.txt
 // NOTE: Unlike many common web-safe encodings, this function does not escape
 // the '=' character. This is to match the expectations set by Android.
 // TODO(isherman): There are several (semantically slightly different)
 // implementations of this within the Chromium codebase. Try to unify them.
 void Base64UrlEncode(const std::string& decoded_input,
                      std::string* encoded_output);
 
 // The inverse operation for the base64url encoding above.
 bool Base64UrlDecode(const std::string& encoded_input,
                      std::string* decoded_output);
 
 }  // namespace proximity_auth
 
 #endif  // COMPONENTS_PROXIMITY_BASE64URL_H