Track SimpleCache memory usage in net/ MemoryDumpProvider

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 <utility>
 
 #include "base/bind.h"
@@ skipping 463 matching lines @@
 
 std::unique_ptr<HttpTransactionFactory>
 HttpCache::SetHttpNetworkTransactionFactoryForTesting(
     std::unique_ptr<HttpTransactionFactory> new_network_layer) {
   std::unique_ptr<HttpTransactionFactory> old_network_layer(
       std::move(network_layer_));
   network_layer_ = std::move(new_network_layer);
   return old_network_layer;
 }
 
+void HttpCache::DumpMemoryStats(base::trace_event::ProcessMemoryDump* pmd,
+                                const std::string& parent_absolute_name) const {
+  if (disk_cache_)
+    disk_cache_->DumpMemoryStats(pmd, parent_absolute_name);

[ssid, 2017/01/31 22:24:19]

Are the other members here insignificant? like active_entries_, doomed_entries_,
playback_cache_map_ and network_layer_.

[xunjieli, 2017/02/01 01:15:52]

I don't know. I haven't seen those in traces that I obtained. Let's tackle those
in a follow-up. I added TODO.

+}
+
 //-----------------------------------------------------------------------------
 
 int HttpCache::CreateBackend(disk_cache::Backend** backend,
                              const CompletionCallback& callback) {
   if (!backend_factory_.get())
     return ERR_FAILED;
 
   building_backend_ = true;
 
   std::unique_ptr<WorkItem> item =
@@ skipping 660 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