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 6a5dc83c35482bc22c07d1ba4fd367f31a76fa7f..d24721126303814ae0230a8ffe51a0f45af66e56 100644
--- a/net/http/http_response_headers.h
+++ b/net/http/http_response_headers.h
@@ -190,25 +190,32 @@ 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
+  // 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 GetFreshnessExpiry(base::Time request_time,
+                                base::Time response_time) const;
+
+  // 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;
+  // received at |response_time|.
+  bool RequiresValidation(base::Time request_time,
+                          base::Time response_time,
+                          base::Time current_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;
+  base::TimeDelta GetFreshnessLifetime(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;
+  // Returns the time at which this resource had age zero. |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 GetFreshnessOrigin(base::Time request_time,
+                                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