Plumb network stack information about existence of cached copy

net/http/http_cache.cc

 // 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.
 
 #include "net/http/http_cache.h"
 
 #include <algorithm>
 
 #include "base/compiler_specific.h"
 
@@ skipping 424 matching lines @@
 HttpCache* HttpCache::GetCache() {
   return this;
 }
 
 HttpNetworkSession* HttpCache::GetSession() {
   net::HttpNetworkLayer* network =
       static_cast<net::HttpNetworkLayer*>(network_layer_.get());
   return network->GetSession();
 }
 
+scoped_ptr<HttpTransactionFactory> HttpCache::SetNetworkLayerForTesting(
+    scoped_ptr<HttpTransactionFactory> new_network_layer) {
+  scoped_ptr<HttpTransactionFactory> old_network_layer(network_layer_.Pass());
+  network_layer_ = new_network_layer.Pass();
+  return old_network_layer.Pass();
+}
+
 //-----------------------------------------------------------------------------
 
 int HttpCache::CreateBackend(disk_cache::Backend** backend,
                              const net::CompletionCallback& callback) {
   if (!backend_factory_.get())
     return ERR_FAILED;
 
   building_backend_ = true;
 
   scoped_ptr<WorkItem> item(new WorkItem(WI_CREATE_BACKEND, NULL, callback,
@@ skipping 685 matching lines @@
     building_backend_ = false;
     DeletePendingOp(pending_op);
   }
 
   // The cache may be gone when we return from the callback.
   if (!item->DoCallback(result, disk_cache_.get()))
     item->NotifyTransaction(result, NULL);
 }
 
 }  // namespace net