[net/http auth] Use strings to identify authentication schemes.

net/http/http_auth_challenge_tokenizer.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 "net/http/http_auth_challenge_tokenizer.h"
 
 #include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+#include "net/http/http_util.h"
 
 namespace net {
 
 HttpAuthChallengeTokenizer::HttpAuthChallengeTokenizer(
     std::string::const_iterator begin,
     std::string::const_iterator end)
     : begin_(begin),
       end_(end),
       scheme_begin_(begin),
       scheme_end_(begin),
@@ skipping 36 matching lines @@
 
   // Save the scheme's position.
   scheme_begin_ = tok.token_begin();
   scheme_end_ = tok.token_end();
 
   params_begin_ = scheme_end_;
   params_end_ = end;
   HttpUtil::TrimLWS(&params_begin_, &params_end_);
 }
 
+std::string HttpAuthChallengeTokenizer::NormalizedScheme() const {
+  if (!HttpUtil::IsToken(scheme_begin_, scheme_end_))
+    return std::string();
+  return base::ToLowerASCII(base::StringPiece(scheme_begin_, scheme_end_));
+}
+
+bool HttpAuthChallengeTokenizer::SchemeIs(
+    const base::StringPiece& scheme) const {
+  DCHECK(base::ToLowerASCII(scheme) == scheme);
+  return base::LowerCaseEqualsASCII(
+      base::StringPiece(scheme_begin_, scheme_end_), scheme);
+}
+
 }  // namespace net