Suppress pause-and-buffer behavior when the HTTP response won't satisfy future requests via cache.

net/http/http_util.h

 // Copyright (c) 2012 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_HTTP_HTTP_UTIL_H_
 #define NET_HTTP_HTTP_UTIL_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/string_tokenizer.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/net_export.h"
 #include "net/http/http_byte_range.h"
+#include "net/http/http_version.h"
 
 // This is a macro to support extending this string literal at compile time.
 // Please excuse me polluting your global namespace!
 #define HTTP_LWS " \t"
 
 namespace net {
 
 class NET_EXPORT HttpUtil {
  public:
   // Returns the absolute path of the URL, to be used for the http request.
@@ skipping 153 matching lines @@
   // it will return 'utf-8,*;q=0.5'. Otherwise (e.g. 'euc-jp'), it'll return
   // 'euc-jp,utf-8;q=0.7,*;q=0.3'.
   static std::string GenerateAcceptCharsetHeader(const std::string& charset);
 
   // Helper. If |*headers| already contains |header_name| do nothing,
   // otherwise add <header_name> ": " <header_value> to the end of the list.
   static void AppendHeaderIfMissing(const char* header_name,
                                     const std::string& header_value,
                                     std::string* headers);
 
+  // Returns true if the parameters describe a response with a strong etag or
+  // last-modified header.  See section 13.3.3 of RFC 2616.
+  static bool HasStrongValidators(HttpVersion version,
+                                  const std::string& etag_header,
+                                  const std::string& last_modified_header,
+                                  const std::string& date_header);
+
   // Used to iterate over the name/value pairs of HTTP headers.  To iterate
   // over the values in a multi-value header, use ValuesIterator.
   // See AssembleRawHeaders for joining line continuations (this iterator
   // does not expect any).
   class NET_EXPORT HeadersIterator {
    public:
     HeadersIterator(std::string::const_iterator headers_begin,
                     std::string::const_iterator headers_end,
                     const std::string& line_delimiter);
     ~HeadersIterator();
@@ skipping 142 matching lines @@
     // into the original's unquoted_value_ member.
     std::string unquoted_value_;
 
     bool value_is_quoted_;
   };
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_UTIL_H_