[tracing] Support background mode in dom storage memory dumps

content/browser/dom_storage/dom_storage_area.cc

 // Copyright 2013 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_area.h"
 
 #include <algorithm>
 #include <cctype>  // for std::isalnum
 
 #include "base/bind.h"
@@ skipping 320 matching lines @@
 
   bool success = task_runner_->PostShutdownBlockingTask(
       FROM_HERE,
       DOMStorageTaskRunner::COMMIT_SEQUENCE,
       base::Bind(&DOMStorageArea::ShutdownInCommitSequence, this));
   DCHECK(success);
 }
 
 void DOMStorageArea::OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) {
   DCHECK(task_runner_->IsRunningOnPrimarySequence());
-  // Do not trace if usage is very low.
-  if (map_->bytes_used() < 1024)
+  if (!is_initial_import_done_)
     return;
 
   // Limit the url length to 50 and strip special characters.
   std::string url = origin_.spec().substr(0, 50);
   for (size_t index = 0; index < url.size(); ++index) {
     if (!std::isalnum(url[index]))
       url[index] = '_';
   }
   std::string name = StringPrintf("dom_storage/%s/%p", url.c_str(), this);
-  auto mad = pmd->CreateAllocatorDump(name + "/storage_map");
-  mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
-                 base::trace_event::MemoryAllocatorDump::kUnitsBytes,
-                 map_->bytes_used());
 
   const char* system_allocator_name =
       base::trace_event::MemoryDumpManager::GetInstance()
           ->system_allocator_pool_name();
+  if (commit_batch_) {
+    auto commit_batch_mad = pmd->CreateAllocatorDump(name + "/commit_batch");
+    commit_batch_mad->AddScalar(
+        base::trace_event::MemoryAllocatorDump::kNameSize,
+        base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+        commit_batch_->GetDataSize());
+    if (system_allocator_name)
+      pmd->AddSuballocation(commit_batch_mad->guid(), system_allocator_name);
+  }
+
+  // Do not add storage map usage if less than 1KB.
+  if (map_->bytes_used() < 1024)
+    return;
+
+  auto map_mad = pmd->CreateAllocatorDump(name + "/storage_map");
+  map_mad->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
+                     base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+                     map_->bytes_used());
   if (system_allocator_name)
-    pmd->AddSuballocation(mad->guid(), system_allocator_name);
+    pmd->AddSuballocation(map_mad->guid(), system_allocator_name);
   // TODO(ssid): Add memory usage of local backing storage crbug.com/605785.
 }
 
 void DOMStorageArea::InitialImportIfNeeded() {
   if (is_initial_import_done_)
     return;
 
   DCHECK(backing_.get());
 
   base::TimeTicks before = base::TimeTicks::Now();
@@ skipping 135 matching lines @@
         commit_batch_->clear_all_first,
         commit_batch_->changed_values);
     DCHECK(success);
   }
   commit_batch_.reset();
   backing_.reset();
   session_storage_backing_ = NULL;
 }
 
 }  // namespace content