Add trace to the caller of QuotaManager::GetAvailableSpace

chrome/browser/sync_file_system/local/canned_syncable_file_system.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 "chrome/browser/sync_file_system/local/canned_syncable_file_system.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/guid.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/thread_task_runner_handle.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/sync_file_system/file_change.h"
 #include "chrome/browser/sync_file_system/local/local_file_change_tracker.h"
 #include "chrome/browser/sync_file_system/local/local_file_sync_context.h"
 #include "chrome/browser/sync_file_system/local/sync_file_system_backend.h"
 #include "chrome/browser/sync_file_system/syncable_file_system_util.h"
 #include "content/public/test/mock_blob_url_request_context.h"
 #include "content/public/test/mock_special_storage_policy.h"
 #include "content/public/test/test_file_system_options.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/fileapi/external_mount_points.h"
@@ skipping 679 matching lines @@
   operation_runner()->Write(url_request_context, url,
                             helper->scoped_text_blob()->GetBlobDataHandle(), 0,
                             base::Bind(&WriteHelper::DidWrite,
                                        base::Owned(helper), callback));
 }
 
 void CannedSyncableFileSystem::DoGetUsageAndQuota(
     int64* usage,
     int64* quota,
     const storage::StatusCallback& callback) {
+  // crbug.com/349708
+  TRACE_EVENT0("io", "CannedSyncableFileSystem::DoGetUsageAndQuota");
+
   EXPECT_TRUE(io_task_runner_->RunsTasksOnCurrentThread());
   EXPECT_TRUE(is_filesystem_opened_);
   DCHECK(quota_manager_.get());
   quota_manager_->GetUsageAndQuota(
       origin_, storage_type(),
       base::Bind(&DidGetUsageAndQuota, callback, usage, quota));
 }
 
 void CannedSyncableFileSystem::DidOpenFileSystem(
     base::SingleThreadTaskRunner* original_task_runner,
@@ skipping 27 matching lines @@
   sync_status_ = status;
   quit_closure.Run();
 }
 
 void CannedSyncableFileSystem::InitializeSyncStatusObserver() {
   ASSERT_TRUE(io_task_runner_->RunsTasksOnCurrentThread());
   backend()->sync_context()->sync_status()->AddObserver(this);
 }
 
 }  // namespace sync_file_system