Add GetExpirationTimes() to HttpResponseHeader.

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 deba3b6d974fd45c42f20d8b7f94b14182d1573f..84234dbc9729d63db66071e9b287058d193497b2 100644
--- a/net/http/http_response_headers.h
+++ b/net/http/http_response_headers.h
@@ -190,25 +190,17 @@ class NET_EXPORT HttpResponseHeaders
   // redirect.
   static bool IsRedirectResponseCode(int response_code);
 
-  // Returns true if the response cannot be reused without validation.  The
-  // result is relative to the current_time parameter, which is a parameter to
-  // support unit testing.  The request_time parameter indicates the time at
-  // which the request was made that resulted in this response, which was
-  // received at response_time.
-  bool RequiresValidation(const base::Time& request_time,
-                          const base::Time& response_time,
-                          const base::Time& current_time) const;
+  // Returns the time from which this resource can no longer be reused without
+  // validation. |request_time| is the local time at which the request that
+  // resulted in this response was made. |response_time| is the local time at
+  // which we received this response.
+  base::Time GetExpirationTime(base::Time request_time,
+                               base::Time response_time) const;
 
   // Returns the amount of time the server claims the response is fresh from
   // the time the response was generated.  See section 13.2.4 of RFC 2616.  See
   // RequiresValidation for a description of the response_time parameter.
-  base::TimeDelta GetFreshnessLifetime(const base::Time& response_time) const;
-
-  // Returns the age of the response.  See section 13.2.3 of RFC 2616.
-  // See RequiresValidation for a description of this method's parameters.
-  base::TimeDelta GetCurrentAge(const base::Time& request_time,
-                                const base::Time& response_time,
-                                const base::Time& current_time) const;
+  base::TimeDelta GetFreshnessLifetime(base::Time response_time) const;
 
   // The following methods extract values from the response headers.  If a
   // value is not present, then false is returned.  Otherwise, true is returned