Remove Hung plugin detector

chrome/browser/hang_monitor/hung_window_detector.h

-// Copyright (c) 2010 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 CHROME_BROWSER_HANG_MONITOR_HUNG_WINDOW_DETECTOR_H__
-#define CHROME_BROWSER_HANG_MONITOR_HUNG_WINDOW_DETECTOR_H__
-
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "chrome/common/worker_thread_ticker.h"
-
-// This class provides the following functionality:
-// Given a top-level window handle, it enumerates all descendant windows
-// of that window and, on finding a window that belongs to a different
-// thread from that of the top-level window, it tests to see if that window
-// is responding to messages. It does this test by first calling the
-// IsHungAppWindow API and, additionally (since the IsHungAppWindow API
-// does not deal correctly with suspended threads), send a dummy message
-// (WM_NULL) to the window and verifies that the call does not timeout.
-// This class is typically used in conjunction with the WorkerThreadTicker
-// class so that the checking can happen on a periodic basis.
-// If a hung window is detected it calls back the specified implementation of
-// the HungWindowNotification interface. Currently this class only supports
-// a single callback but it can be extended later to support multiple
-// callbacks.
-class HungWindowDetector : public WorkerThreadTicker::Callback {
- public:
-  // This property specifies the message timeout for a child window.
-  static const wchar_t kHungChildWindowTimeout[];
-  // This is the notification callback interface that is used to notify
-  // callers about a non-responsive window
-  class HungWindowNotification  {
-   public:
-    enum ActionOnHungWindow {
-      HUNG_WINDOW_IGNORE,
-      HUNG_WINDOW_TERMINATE_PROCESS,
-    };
-
-    // This callback method is invoked when a hung window is detected.
-    // A return value of false indicates that we should stop enumerating the
-    // child windows of the browser window to check if they are hung.
-    virtual bool OnHungWindowDetected(HWND hung_window, HWND top_level_window,
-                                      ActionOnHungWindow* action) = 0;
-  };
-
-  // The notification object is not owned by this class. It is assumed that
-  // this pointer will be valid throughout the lifetime of this class.
-  // Ownership of this pointer is not transferred to this class.
-  // Note that the Initialize method needs to be called to initiate monitoring
-  // of hung windows.
-  explicit HungWindowDetector(HungWindowNotification* notification);
-  ~HungWindowDetector() override;
-
-  // This method initialized the monitoring of hung windows. All descendant
-  // windows of the passed-in top-level window which belong to a thread
-  // different from that of the top-level window are monitored. The
-  // message_response_timeout parameter indicates how long this class must
-  // wait for a window to respond to a sent message before it is considered
-  // to be non-responsive.
-  // Initialize can be called multiple times to change the actual window to
-  // be monitored as well as the message response timeout
-  bool Initialize(HWND top_level_window,
-                  int message_response_timeout);
-
-  // Implementation of the WorkerThreadTicker::Callback interface
-  void OnTick() override;
-
- private:
-  // Helper function that checks whether the specified child window is hung.
-  // If so, it invokes the HungWindowNotification interface implementation
-  bool CheckChildWindow(HWND child_window);
-
-  static BOOL CALLBACK ChildWndEnumProc(HWND child_window, LPARAM param);
-
-  // Pointer to the HungWindowNotification callback interface. This class does
-  // not RefCount this pointer and it is assumed that the pointer will be valid
-  // throughout the lifetime of this class.
-  HungWindowNotification* notification_;
-  HWND top_level_window_;
-
-  // How long do we wait before we consider a window hung (in ms)
-  int message_response_timeout_;
-  base::Lock hang_detection_lock_;
-  // Indicates if this object is currently enumerating hung windows
-  bool enumerating_;
-
-  DISALLOW_COPY_AND_ASSIGN(HungWindowDetector);
-};
-
-
-#endif  // CHROME_BROWSER_HANG_MONITOR_HUNG_WINDOW_DETECTOR_H__