Initial implementation of Chrome-Freshness header.

net/http/http_response_headers.h

Index: net/http/http_response_headers.h
diff --git a/net/http/http_response_headers.h b/net/http/http_response_headers.h
index 2d306c95ca048aaa4dad94528c2f87a819c11d5d..ddab798c0a2c0795556d1b2da0a583574c581553 100644
--- a/net/http/http_response_headers.h
+++ b/net/http/http_response_headers.h
@@ -229,6 +229,7 @@ class NET_EXPORT HttpResponseHeaders
   bool GetDateValue(base::Time* value) const;
   bool GetLastModifiedValue(base::Time* value) const;
   bool GetExpiresValue(base::Time* value) const;
+  bool GetStaleWhileRevalidateValue(base::TimeDelta* value) const;
 
   // Extracts the time value of a particular header.  This method looks for the
   // first matching header value and parses its value as a HTTP-date.
@@ -320,6 +321,12 @@ class NET_EXPORT HttpResponseHeaders
   // index |from|.  Returns string::npos if not found.
   size_t FindHeader(size_t from, const base::StringPiece& name) const;
 
+  // Search the Cache-Control header for a directive matching |directive|. If
+  // present, treat its value as a time offset in seconds, write it to |result|,
+  // and return true.
+  bool GetCacheControlDirective(const base::StringPiece& directive,
+                                base::TimeDelta* result) const;
+
   // Add a header->value pair to our list.  If we already have header in our
   // list, append the value to it.
   void AddHeader(std::string::const_iterator name_begin,