Adding a Find method to the HeadersIterator class....

net/http/http_util.cc

 // Copyright (c) 2006-2008 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.
 
 // The rules for parsing content-types were borrowed from Firefox:
 // http://lxr.mozilla.org/mozilla/source/netwerk/base/src/nsURLHelper.cpp#834
 
 #include "net/http/http_util.h"
 
 #include <algorithm>
@@ skipping 624 matching lines @@
 
     values_begin_ = colon + 1;
     TrimLWS(&values_begin_, &values_end_);
 
     // if we got a header name, then we are done.
     return true;
   }
   return false;
 }
 
+bool HttpUtil::HeadersIterator::AdvanceTo(const char* name) {
+  DCHECK(name != NULL);
+  DCHECK_EQ(0, StringToLowerASCII<std::string>(name).compare(name))
+      << "the header name must be in all lower case";
+
+  while (GetNext()) {
+    if (LowerCaseEqualsASCII(name_begin_, name_end_, name)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 HttpUtil::ValuesIterator::ValuesIterator(
     string::const_iterator values_begin,
     string::const_iterator values_end,
     char delimiter)
     : values_(values_begin, values_end, string(1, delimiter)) {
   values_.set_quote_chars("\'\"");
 }
 
 bool HttpUtil::ValuesIterator::GetNext() {
   while (values_.GetNext()) {
     value_begin_ = values_.token_begin();
     value_end_ = values_.token_end();
     TrimLWS(&value_begin_, &value_end_);
 
     // bypass empty values.
     if (value_begin_ != value_end_)
       return true;
   }
   return false;
 }
 
 }  // namespace net