[tracing] Support background mode in dom storage memory dumps

content/browser/dom_storage/dom_storage_context_impl.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 "content/browser/dom_storage/dom_storage_context_impl.h"
 
 #include <stddef.h>
 #include <stdlib.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
 #include "base/guid.h"
 #include "base/location.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "content/browser/dom_storage/dom_storage_area.h"
 #include "content/browser/dom_storage/dom_storage_database.h"
 #include "content/browser/dom_storage/dom_storage_namespace.h"
 #include "content/browser/dom_storage/dom_storage_task_runner.h"
 #include "content/browser/dom_storage/session_storage_database.h"
 #include "content/common/dom_storage/dom_storage_types.h"
@@ skipping 434 matching lines @@
       "LocalStorage.BrowserLocalStorageCachePurgedInKB",
       (initial_stats.total_cache_size -
        GetTotalNamespaceStatistics(namespaces_).total_cache_size) /
           1024,
       1, 100000, 50);
 }
 
 bool DOMStorageContextImpl::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
+  if (session_storage_database_)
+    session_storage_database_->OnMemoryDump(pmd);
+  if (args.level_of_detail ==
+      base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND) {
+    DOMStorageNamespace::UsageStatistics total_stats =
+        GetTotalNamespaceStatistics(namespaces_);
+    auto mad = pmd->CreateAllocatorDump(
+        StringPrintf("dom_storage/%p/cache_size", this));
+    mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                   base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                   total_stats.total_cache_size);
+    mad->AddScalar("inactive_areas",
+                   base::trace_event::MemoryAllocatorDump::kUnitsObjects,
+                   total_stats.inactive_area_count);
+    mad->AddScalar("total_areas",
+                   base::trace_event::MemoryAllocatorDump::kUnitsObjects,
+                   total_stats.total_area_count);
+    return true;
+  }
   for (const auto& it : namespaces_) {
     it.second->OnMemoryDump(pmd);
   }
-  if (session_storage_database_)
-    session_storage_database_->OnMemoryDump(pmd);
   return true;
 }
 
 void DOMStorageContextImpl::FindUnusedNamespaces() {
   DCHECK(session_storage_database_.get());
   if (scavenging_started_)
     return;
   scavenging_started_ = true;
   std::set<std::string> namespace_ids_in_use;
   for (StorageNamespaceMap::const_iterator it = namespaces_.begin();
@@ skipping 53 matching lines @@
   if (!deletable_persistent_namespace_ids_.empty()) {
     task_runner_->PostDelayedTask(
         FROM_HERE, base::Bind(
             &DOMStorageContextImpl::DeleteNextUnusedNamespace,
             this),
         base::TimeDelta::FromSeconds(kSessionStoraceScavengingSeconds));
   }
 }
 
 }  // namespace content