Revert of Revert 221427 "Add instrumentation to the MessagePumpMac family ..."

base/message_loop/message_loop.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 "base/message_loop/message_loop.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 614 matching lines @@
 bool MessageLoop::DoIdleWork() {
   if (ProcessNextDelayedNonNestableTask())
     return true;
 
   if (run_loop_->quit_when_idle_received_)
     pump_->Quit();
 
   return false;
 }
 
+void MessageLoop::GetQueueingInformation(size_t* queue_size,
+                                         TimeDelta* queueing_delay) {
+  *queue_size = work_queue_.size();
+  if (*queue_size == 0) {
+    *queueing_delay = TimeDelta();
+    return;
+  }
+
+  const PendingTask& next_to_run = work_queue_.front();
+  tracked_objects::Duration duration =
+      tracked_objects::TrackedTime::Now() - next_to_run.EffectiveTimePosted();
+  *queueing_delay = TimeDelta::FromMilliseconds(duration.InMilliseconds());
+}
+
 void MessageLoop::DeleteSoonInternal(const tracked_objects::Location& from_here,
                                      void(*deleter)(const void*),
                                      const void* object) {
   PostNonNestableTask(from_here, Bind(deleter, object));
 }
 
 void MessageLoop::ReleaseSoonInternal(
     const tracked_objects::Location& from_here,
     void(*releaser)(const void*),
     const void* object) {
@@ skipping 82 matching lines @@
       persistent,
       mode,
       controller,
       delegate);
 }
 #endif
 
 #endif  // !defined(OS_NACL)
 
 }  // namespace base