[SyncFS] Add EVENT_TRACE to SyncTaskToken

chrome/browser/sync_file_system/drive_backend/sync_task_token.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 "chrome/browser/sync_file_system/drive_backend/sync_task_token.h"
 
 #include "base/bind.h"
+#include "base/debug/trace_event.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task_manager.h"
 #include "chrome/browser/sync_file_system/drive_backend/task_dependency_manager.h"
 
 namespace sync_file_system {
 namespace drive_backend {
 
 const int64 SyncTaskToken::kTestingTaskTokenID = -1;
 const int64 SyncTaskToken::kForegroundTaskTokenID = 0;
 const int64 SyncTaskToken::kMinimumBackgroundTaskTokenID = 1;
 
@@ skipping 72 matching lines @@
 }
 
 void SyncTaskToken::clear_blocking_factor() {
   blocking_factor_.reset();
 }
 
 void SyncTaskToken::InitializeTaskLog(const std::string& task_description) {
   task_log_.reset(new TaskLogger::TaskLog);
   task_log_->start_time = base::TimeTicks::Now();
   task_log_->task_description = task_description;
+
+  TRACE_EVENT_ASYNC_BEGIN1(
+      TRACE_DISABLED_BY_DEFAULT("SyncFileSystem"),
+      "SyncTask", task_log_->log_id,
+      "task_description", task_description);
 }
 
 void SyncTaskToken::FinalizeTaskLog(const std::string& result_description) {
+  TRACE_EVENT_ASYNC_END1(
+      TRACE_DISABLED_BY_DEFAULT("SyncFileSystem"),
+      "SyncTask", task_log_->log_id,
+      "result_description", result_description);
+
   DCHECK(task_log_);
   task_log_->result_description = result_description;
   task_log_->end_time = base::TimeTicks::Now();
 }
 
 void SyncTaskToken::RecordLog(const std::string& message) {
   DCHECK(task_log_);
   task_log_->details.push_back(message);
 }
 
@@ skipping 10 matching lines @@
                              scoped_ptr<BlockingFactor> blocking_factor,
                              const SyncStatusCallback& callback)
     : manager_(manager),
       token_id_(token_id),
       callback_(callback),
       blocking_factor_(blocking_factor.Pass()) {
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system