Add trace to the caller of QuotaManager::GetAvailableSpace

storage/browser/fileapi/sandbox_file_stream_writer.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 "storage/browser/fileapi/sandbox_file_stream_writer.h"
 
 #include "base/files/file_util_proxy.h"
 #include "base/sequenced_task_runner.h"
+#include "base/trace_event/trace_event.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "storage/browser/fileapi/file_observers.h"
 #include "storage/browser/fileapi/file_stream_reader.h"
 #include "storage/browser/fileapi/file_system_context.h"
 #include "storage/browser/fileapi/file_system_operation_runner.h"
 #include "storage/browser/quota/quota_manager_proxy.h"
 #include "storage/common/fileapi/file_system_util.h"
 
 namespace storage {
@@ skipping 125 matching lines @@
   storage::QuotaManagerProxy* quota_manager_proxy =
       file_system_context_->quota_manager_proxy();
   if (!quota_manager_proxy) {
     // If we don't have the quota manager or the requested filesystem type
     // does not support quota, we should be able to let it go.
     allowed_bytes_to_write_ = default_quota_;
     callback.Run(net::OK);
     return;
   }
 
+  // crbug.com/349708
+  TRACE_EVENT0("io", "SandboxFileStreamWriter::DidCreateSnapshotFile");
+
   DCHECK(quota_manager_proxy->quota_manager());
   quota_manager_proxy->quota_manager()->GetUsageAndQuota(
       url_.origin(),
       FileSystemTypeToQuotaStorageType(url_.type()),
       base::Bind(&SandboxFileStreamWriter::DidGetUsageAndQuota,
                  weak_factory_.GetWeakPtr(), callback));
 }
 
 void SandboxFileStreamWriter::DidGetUsageAndQuota(
     const net::CompletionCallback& callback,
@@ skipping 73 matching lines @@
   DCHECK(cancel_callback_.is_null());
 
   // Write() is not called yet, so there's nothing to flush.
   if (!local_file_writer_)
     return net::OK;
 
   return local_file_writer_->Flush(callback);
 }
 
 }  // namespace storage