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

base/message_loop/message_pump_win.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_WIN_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_WIN_H_
 
 #include <windows.h>
 
 #include <list>
@@ skipping 146 matching lines @@
   ~MessagePumpForGpu() override;
 
   // Factory methods.
   static void InitFactory();
   static std::unique_ptr<MessagePump> CreateMessagePumpForGpu();
 
   // MessagePump methods:
   void ScheduleWork() override;
   void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
 
+  // 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.
+  bool WasSignaled() override;
+
  private:
   // MessagePumpWin methods:
   void DoRunLoop() override;
 
   void WaitForWork();
   bool ProcessNextMessage();
 
   const HANDLE event_;
 
   // Used to help diagnose hangs.
@@ skipping 107 matching lines @@
   // The completion port associated with this thread.
   win::ScopedHandle port_;
   // This list will be empty almost always. It stores IO completions that have
   // not been delivered yet because somebody was doing cleanup.
   std::list<IOItem> completed_io_;
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_WIN_H_