Hotlist Slow: Remove extra thread pool created by VolumeMountWatcherWin.

components/storage_monitor/volume_mount_watcher_win.h

 // Copyright 2014 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 COMPONENTS_STORAGE_MONITOR_VOLUME_MOUNT_WATCHER_WIN_H_
 #define COMPONENTS_STORAGE_MONITOR_VOLUME_MOUNT_WATCHER_WIN_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/string16.h"
-#include "base/threading/sequenced_worker_pool.h"
 #include "components/storage_monitor/storage_info.h"
 #include "components/storage_monitor/storage_monitor.h"
 
 namespace storage_monitor {
 
 class TestVolumeMountWatcherWin;
 
 // This class watches the volume mount points and sends notifications to
 // StorageMonitor about the device attach/detach events.
 // This is a singleton class instantiated by StorageMonitorWin.
@@ skipping 53 matching lines @@
       const base::FilePath& device_path,
       const GetDeviceDetailsCallbackType& get_device_details_callback,
       base::WeakPtr<VolumeMountWatcherWin> volume_watcher);
 
   // Mark that a device we started a metadata check for has completed.
   virtual void DeviceCheckComplete(const base::FilePath& device_path);
 
   virtual GetAttachedDevicesCallbackType GetAttachedDevicesCallback() const;
   virtual GetDeviceDetailsCallbackType GetDeviceDetailsCallback() const;
 
-  // Worker pool used to collect device information. Used because some
-  // devices freeze workers trying to get device info, resulting in
-  // shutdown hangs.
-  scoped_refptr<base::SequencedWorkerPool> device_info_worker_pool_;
-  scoped_refptr<base::SequencedTaskRunner> task_runner_;
+  // Used for device info calls that may take a long time.
+  scoped_refptr<base::SequencedTaskRunner> device_info_task_runner_;
 
  private:
   friend class TestVolumeMountWatcherWin;
 
   // Key: Mass storage device mount point.
   // Value: Mass storage device metadata.
   typedef std::map<base::FilePath, StorageInfo> MountPointDeviceMetadataMap;
 
   // Maintain a set of device attribute check calls in-flight. Only accessed
   // on the UI thread. This is to try and prevent the same device from
   // occupying our worker pool in case of windows API call hangs.
   std::set<base::FilePath> pending_device_checks_;
 
   // A map from device mount point to device metadata. Only accessed on the UI
   // thread.
   MountPointDeviceMetadataMap device_metadata_;
 
   // The notifications object to use to signal newly attached volumes. Only
   // removable devices will be notified.
   StorageMonitor::Receiver* notifications_;
 
   base::WeakPtrFactory<VolumeMountWatcherWin> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VolumeMountWatcherWin);
 };
 
 }  // namespace storage_monitor
 
 #endif  // COMPONENTS_STORAGE_MONITOR_VOLUME_MOUNT_WATCHER_WIN_H_