Revert of Verify if GPU message pump is signaled when it hangs in WaitForWork

base/message_loop/message_pump.h

 // 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.
 
 #ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_H_
 
 #include "base/base_export.h"
 #include "base/message_loop/timer_slack.h"
 #include "base/threading/non_thread_safe.h"
@@ skipping 106 matching lines @@
   // until it returns a value of false.
   virtual void ScheduleWork() = 0;
 
   // Schedule a DoDelayedWork callback to happen at the specified time,
   // cancelling any pending DoDelayedWork callback.  This method may only be
   // used on the thread that called Run.
   virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) = 0;
 
   // Sets the timer slack to the specified value.
   virtual void SetTimerSlack(TimerSlack timer_slack);
-
-#if defined(OS_WIN)
-  // TODO (stanisc): crbug.com/596190: Remove this after the signaling issue
-  // has been investigated.
-  // This should be used for diagnostic only. If message pump wake-up mechanism
-  // is based on auto-reset event this call would reset the event to unset
-  // state.
-  virtual bool WasSignaled();
-#endif
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_H_