Revert of GPU Watchdog to check I/O before terminating GPU process

content/gpu/gpu_watchdog_thread.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 CONTENT_GPU_GPU_WATCHDOG_THREAD_H_
 #define CONTENT_GPU_GPU_WATCHDOG_THREAD_H_
 
-#include "base/files/file.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/power_monitor/power_observer.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "gpu/ipc/service/gpu_watchdog.h"
 #include "ui/gfx/native_widget_types.h"
@@ skipping 49 matching lines @@
     void DidProcessTask(const base::PendingTask& pending_task) override;
 
    private:
     GpuWatchdogThread* watchdog_;
   };
 
   ~GpuWatchdogThread() override;
 
   void OnAcknowledge();
   void OnCheck(bool after_suspend);
-  void BeginTerminating();
   void DeliberatelyTerminateToRecoverFromHang();
 #if defined(USE_X11)
   void SetupXServer();
   void SetupXChangeProp();
   bool MatchXEventAtom(XEvent* event);
 #endif
 
   void OnAddPowerObserver();
 
   // Implement PowerObserver.
@@ skipping 37 matching lines @@
   bool suspended_;
 
   // The time the last OnSuspend and OnResume was called.
   base::Time suspend_time_;
   base::Time resume_time_;
 
   // This is the time the last check was sent.
   base::Time check_time_;
   base::TimeTicks check_timeticks_;
 
-#if defined(OS_WIN)
-  // Writing to this temp file is used as an additional step before crashing the
-  // process. That should help to distinguish true hangs from the cases when the
-  // watched thread is running slow being blocked on hard faults or other I/O.
-  base::File temp_file_for_io_checking_;
-  base::TimeDelta io_check_duration_;
-#endif
-
 #if defined(USE_X11)
   XDisplay* display_;
   gfx::AcceleratedWidget window_;
   XAtom atom_;
   FILE* tty_file_;
   int host_tty_;
 #endif
 
   base::WeakPtrFactory<GpuWatchdogThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuWatchdogThread);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_GPU_GPU_WATCHDOG_THREAD_H_