[NOT FOR REVIEW] Instrument net/ with trace events.

net/disk_cache/blockfile/in_flight_io.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 "net/disk_cache/blockfile/in_flight_io.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/trace_event/trace_event.h"
 
 namespace disk_cache {
 
 BackgroundIO::BackgroundIO(InFlightIO* controller)
     : result_(-1), io_completed_(true, false), controller_(controller) {
 }
 
 // Runs on the primary thread.
 void BackgroundIO::OnIOSignalled() {
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/477117 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("477117 BackgroundIO::OnIOSignalled"));
+  TRACE_EVENT0("net", "net::BackgroundIO::OnIOSignalled");
   if (controller_)
     controller_->InvokeCallback(this, false);
 }
 
 void BackgroundIO::Cancel() {
   // controller_ may be in use from the background thread at this time.
   base::AutoLock lock(controller_lock_);
   DCHECK(controller_);
   controller_ = NULL;
 }
@@ skipping 71 matching lines @@
   OnOperationComplete(operation, cancel_task);
 }
 
 // Runs on the primary thread.
 void InFlightIO::OnOperationPosted(BackgroundIO* operation) {
   DCHECK(callback_task_runner_->RunsTasksOnCurrentThread());
   io_list_.insert(make_scoped_refptr(operation));
 }
 
 }  // namespace disk_cache