Add trace to the caller of QuotaManager::GetAvailableSpace

storage/browser/quota/quota_manager_proxy.cc

 // Copyright 2014 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 "storage/browser/quota/quota_manager_proxy.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_runner_util.h"
+#include "base/trace_event/trace_event.h"
 
 namespace storage {
 
 namespace {
 
 void DidGetUsageAndQuota(
     base::SequencedTaskRunner* original_task_runner,
     const QuotaManagerProxy::GetUsageAndQuotaCallback& callback,
     QuotaStatusCode status, int64 usage, int64 quota) {
   if (!original_task_runner->RunsTasksOnCurrentThread()) {
@@ skipping 107 matching lines @@
         FROM_HERE,
         base::Bind(&QuotaManagerProxy::GetUsageAndQuota, this,
                    make_scoped_refptr(original_task_runner),
                    origin, type, callback));
     return;
   }
   if (!manager_) {
     DidGetUsageAndQuota(original_task_runner, callback, kQuotaErrorAbort, 0, 0);
     return;
   }
+
+  // crbug.com/349708
+  TRACE_EVENT0("io", "QuotaManagerProxy::GetUsageAndQuota");
+
   manager_->GetUsageAndQuota(
       origin, type,
       base::Bind(&DidGetUsageAndQuota,
                  make_scoped_refptr(original_task_runner), callback));
 }
 
 QuotaManager* QuotaManagerProxy::quota_manager() const {
   DCHECK(!io_thread_.get() || io_thread_->BelongsToCurrentThread());
   return manager_;
 }
 
 QuotaManagerProxy::QuotaManagerProxy(
     QuotaManager* manager,
     const scoped_refptr<base::SingleThreadTaskRunner>& io_thread)
     : manager_(manager), io_thread_(io_thread) {
 }
 
 QuotaManagerProxy::~QuotaManagerProxy() {
 }
 
 }  // namespace storage