Add instrumentation to the MessagePumpMac family of classes.

base/message_loop/message_loop.h

 // 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.
 
 #ifndef BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 
 #include <queue>
 #include <string>
 
@@ skipping 460 matching lines @@
 
   // Add occurrence of event to our histogram, so that we can see what is being
   // done in a specific MessageLoop instance (i.e., specific thread).
   // If message_histogram_ is NULL, this is a no-op.
   void HistogramEvent(int event);
 
   // MessagePump::Delegate methods:
   virtual bool DoWork() OVERRIDE;
   virtual bool DoDelayedWork(TimeTicks* next_delayed_work_time) OVERRIDE;
   virtual bool DoIdleWork() OVERRIDE;
+  virtual void GetQueueingInformation(size_t* queue_size,
+                                      TimeDelta* queueing_delay) OVERRIDE;
 
   Type type_;
 
   // A list of tasks that need to be processed by this instance.  Note that
   // this queue is only accessed (push/pop) by our current thread.
   TaskQueue work_queue_;
 
   // Contains delayed tasks, sorted by their 'delayed_run_time' property.
   DelayedTaskQueue delayed_work_queue_;
 
@@ skipping 219 matching lines @@
 
 // Do not add any member variables to MessageLoopForIO!  This is important b/c
 // MessageLoopForIO is often allocated via MessageLoop(TYPE_IO).  Any extra
 // data that you need should be stored on the MessageLoop's pump_ instance.
 COMPILE_ASSERT(sizeof(MessageLoop) == sizeof(MessageLoopForIO),
                MessageLoopForIO_should_not_have_extra_member_variables);
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_