Media Galleries: Another round of MTPDeviceDelegateImplLinux cleanup.

chrome/browser/media_galleries/linux/mtp_device_delegate_impl_linux.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 CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_
 
 #include <queue>
 
 #include "base/callback.h"
@@ skipping 77 matching lines @@
   // initialized.
   void EnsureInitAndRunTask(const PendingTaskInfo& task_info);
 
   // Writes data from the device to the snapshot file path based on the
   // parameters in |current_snapshot_request_info_| by doing a call-and-reply to
   // the UI thread.
   //
   // |snapshot_file_info| specifies the metadata details of the snapshot file.
   void WriteDataIntoSnapshotFile(const base::File::Info& snapshot_file_info);
 
+  // Marks the current request as complete and call ProcessNextPendingRequest().
+  void PendingRequestDone();
+
   // Processes the next pending request.
   void ProcessNextPendingRequest();
 
   // Handles the device initialization event. |succeeded| indicates whether
   // device initialization succeeded.
   //
   // If the device is successfully initialized, runs the next pending task.
   void OnInitCompleted(bool succeeded);
 
   // Called when GetFileInfo() succeeds. |file_info| specifies the
@@ skipping 62 matching lines @@
 
   // Handles the device file |error|. |error_callback| is invoked to notify the
   // caller about the file error.
   void HandleDeviceFileError(const ErrorCallback& error_callback,
                              base::File::Error error);
 
   // MTP device initialization state.
   InitializationState init_state_;
 
   // Used to make sure only one task is in progress at any time.
+  // Otherwise the browser will try to send too many requests at once and
+  // overload the device.
   bool task_in_progress_;
 
   // Registered file system device path. This path does not
   // correspond to a real device path (e.g. "/usb:2,2:81282").
   const base::FilePath device_path_;
 
   // MTP device storage name (e.g. "usb:2,2:81282").
   std::string storage_name_;
 
   // A list of pending tasks that needs to be run when the device is
   // initialized or when the current task in progress is complete.
   std::queue<PendingTaskInfo> pending_tasks_;
 
   // Used to track the current snapshot file request. A snapshot file is created
   // incrementally. CreateSnapshotFile request reads the device file and writes
   // to the snapshot file in chunks. In order to retain the order of the
   // snapshot file requests, make sure there is only one active snapshot file
   // request at any time.
   scoped_ptr<SnapshotRequestInfo> current_snapshot_request_info_;
 
   // For callbacks that may run after destruction.
   base::WeakPtrFactory<MTPDeviceDelegateImplLinux> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MTPDeviceDelegateImplLinux);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_