Add queued_time_ms trace for events in message loop

base/threading/worker_pool_posix.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 "base/threading/worker_pool_posix.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
@@ skipping 74 matching lines @@
   const std::string name = base::StringPrintf(
       "%s/%d", name_prefix_.c_str(), PlatformThread::CurrentId());
   // Note |name.c_str()| must remain valid for for the whole life of the thread.
   PlatformThread::SetName(name.c_str());
 
   for (;;) {
     PendingTask pending_task = pool_->WaitForTask();
     if (pending_task.task.is_null())
       break;
     TRACE_EVENT2("task", "WorkerThread::ThreadMain::Run",
-        "src_file", pending_task.posted_from.file_name(),
-        "src_func", pending_task.posted_from.function_name());
+                 "src", pending_task.posted_from.ToTraceFormat(),
+                 "queued_time_ms",
+                 pending_task.DurationSinceExpectedRunTime().InMilliseconds());
 
     TrackedTime start_time =
         tracked_objects::ThreadData::NowForStartOfRun(pending_task.birth_tally);
 
     pending_task.task.Run();
 
     tracked_objects::ThreadData::TallyRunOnWorkerThreadIfTracking(
         pending_task.birth_tally, TrackedTime(pending_task.time_posted),
         start_time, tracked_objects::ThreadData::NowForEndOfRun());
   }
@@ skipping 86 matching lines @@
       return PendingTask(FROM_HERE, base::Closure());
     }
   }
 
   PendingTask pending_task = pending_tasks_.front();
   pending_tasks_.pop();
   return pending_task;
 }
 
 }  // namespace base