Adding histograms showing fraction of page load times

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 391 matching lines @@
                               int buf_len) {
   if (!buf_len)
     return;
 
   // Do lazy initialization of disk cache if needed.
   if (!disk_cache_.get()) {
     // We don't care about the result.
     CreateBackend(NULL, net::CompletionCallback());
   }
 
-  HttpCache::Transaction* trans = new HttpCache::Transaction(this);
+  HttpCache::Transaction* trans = new HttpCache::Transaction(this, NULL);
   MetadataWriter* writer = new MetadataWriter(trans);
 
   // The writer will self destruct when done.
   writer->Write(url, expected_response_time, buf, buf_len);
 }
 
 void HttpCache::CloseAllConnections() {
   net::HttpNetworkLayer* network =
       static_cast<net::HttpNetworkLayer*>(network_layer_.get());
   HttpNetworkSession* session = network->GetSession();
@@ skipping 14 matching lines @@
   if (!disk_cache_.get())
     return;
 
   HttpRequestInfo request_info;
   request_info.url = url;
   request_info.method = http_method;
   std::string key = GenerateCacheKey(&request_info);
   disk_cache_->OnExternalCacheHit(key);
 }
 
-int HttpCache::CreateTransaction(scoped_ptr<HttpTransaction>* trans) {
+int HttpCache::CreateTransaction(scoped_ptr<HttpTransaction>* trans,
+                                 HttpTransactionDelegate* delegate) {
   // Do lazy initialization of disk cache if needed.
   if (!disk_cache_.get()) {
     // We don't care about the result.
     CreateBackend(NULL, net::CompletionCallback());
   }
 
-  trans->reset(new HttpCache::Transaction(this));
+  trans->reset(new HttpCache::Transaction(this, delegate));
   return OK;
 }
 
 HttpCache* HttpCache::GetCache() {
   return this;
 }
 
 HttpNetworkSession* HttpCache::GetSession() {
   net::HttpNetworkLayer* network =
       static_cast<net::HttpNetworkLayer*>(network_layer_.get());
@@ skipping 681 matching lines @@
     building_backend_ = false;
     DeletePendingOp(pending_op);
   }
 
   // The cache may be gone when we return from the callback.
   if (!item->DoCallback(result, backend))
     item->NotifyTransaction(result, NULL);
 }
 
 }  // namespace net