Use int64 time stamp when storing metadata to the HTTP cache.

net/http/http_cache.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.
 
 // This file declares a HttpTransactionFactory implementation that can be
 // layered on top of another HttpTransactionFactory to add HTTP caching.  The
 // caching logic follows RFC 2616 (any exceptions are called out in the code).
 //
 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
 // the cache storage.
@@ skipping 160 matching lines @@
   static bool ParseResponseInfo(const char* data, int len,
                                 HttpResponseInfo* response_info,
                                 bool* response_truncated);
 
   // Writes |buf_len| bytes of metadata stored in |buf| to the cache entry
   // referenced by |url|, as long as the entry's |expected_response_time| has
   // not changed. This method returns without blocking, and the operation will
   // be performed asynchronously without any completion notification.
   void WriteMetadata(const GURL& url,
                      RequestPriority priority,
-                     double expected_response_time,
+                     base::Time expected_response_time,
                      IOBuffer* buf,
                      int buf_len);
 
   // Get/Set the cache's mode.
   void set_mode(Mode value) { mode_ = value; }
   Mode mode() { return mode_; }
 
   // Get/Set the cache's clock. These are public only for testing.
   void SetClockForTesting(scoped_ptr<base::Clock> clock) {
     clock_.reset(clock.release());
@@ skipping 285 matching lines @@
   scoped_ptr<base::Clock> clock_;
 
   base::WeakPtrFactory<HttpCache> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpCache);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_H_