Upstream Chrome on iOS source code [4/11].

ios/chrome/browser/ui/external_file_remover.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 IOS_CHROME_BROWSER_UI_EXTERNAL_FILE_REMOVER_H_
+#define IOS_CHROME_BROWSER_UI_EXTERNAL_FILE_REMOVER_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "components/sessions/core/tab_restore_service_observer.h"
+
+@class BrowserViewController;
+namespace sessions {
+class TabRestoreService;
+}
+
+// ExternalFileRemover is responsible for removing documents received from other
+// applications that are not in the list of recently closed tabs, open tabs or
+// bookmarks.
+class ExternalFileRemover : public sessions::TabRestoreServiceObserver {
+ public:
+  // Creates an ExternalFileRemover to remove external documents not referenced
+  // by the specified BrowserViewController. Use Remove to initiate the removal.
+  explicit ExternalFileRemover(BrowserViewController* bvc);
+  ~ExternalFileRemover() override;
+
+  // sessions::TabRestoreServiceObserver methods
+  void TabRestoreServiceChanged(sessions::TabRestoreService* service) override;
+  void TabRestoreServiceDestroyed(
+      sessions::TabRestoreService* service) override;
+
+  // Post a delayed task to clean up the files received from other applications.
+  // |callback| is called when the clean up has finished.
+  void RemoveAfterDelay(const base::TimeDelta& delay,
+                        const base::Closure& callback);
+
+ private:
+  // Removes files received from other apps. If |all_files| is true, then
+  // all files including files that may be referenced by tabs through restore
+  // service or history. Otherwise, only the unreferenced files are removed.
+  // |callback| is called when the removal finishes.
+  void RemoveFiles(bool all_files, const base::Closure& callback);
+  // Pointer to the tab restore service in the browser state associated with
+  // |bvc_|.
+  sessions::TabRestoreService* tabRestoreService_;
+  // BrowserViewController used to get the referenced files. Must outlive this
+  // object.
+  BrowserViewController* bvc_;
+  // Used to ensure |Remove()| is not run when this object is destroyed.
+  base::WeakPtrFactory<ExternalFileRemover> weak_ptr_factory_;
+  // Loads the |tabRestoreService_| if necessary. Removes all files received
+  // from other apps if |all_files| is true. Otherwise, removes the unreferenced
+  // files only. |callback| is called when the removal finishes.
+  void Remove(bool all_files, const base::Closure& callback);
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_EXTERNAL_FILE_REMOVER_H_