Revert of Don't peek messages in the MessagePumpForUI class when we receive our kMsgHaveWork message.

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 457 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:
   bool DoWork() override;
   bool DoDelayedWork(TimeTicks* next_delayed_work_time) override;
   bool DoIdleWork() override;
-  TimeTicks GetNewlyAddedTaskDelay() override;
 
   const 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_;
 
 #if defined(OS_WIN)
   // How many high resolution tasks are in the pending task queue. This value
   // increases by N every time we call ReloadWorkQueue() and decreases by 1
@@ skipping 195 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_