MessagePumpForGpu - reduce potential work processing starvation

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 154 matching lines @@
   void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
 
  private:
   // MessagePumpWin methods:
   void DoRunLoop() override;
 
   void WaitForWork();
   bool ProcessNextMessage();
 
   const HANDLE event_;
+
+  // Used to help diagnose hangs.
+  // TODO(stanisc): crbug.com/596190: Remove these once the bug is fixed.
+  TimeTicks last_set_event_timeticks_;
 };
 
 //-----------------------------------------------------------------------------
 // MessagePumpForIO extends MessagePumpWin with methods that are particular to a
 // MessageLoop instantiated with TYPE_IO. This version of MessagePump does not
 // deal with Windows mesagges, and instead has a Run loop based on Completion
 // Ports so it is better suited for IO operations.
 //
 class BASE_EXPORT MessagePumpForIO : public MessagePumpWin {
  public:
@@ skipping 95 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_