Replace the DownloadFileManager with direct ownership

content/public/browser/download_destination_observer.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_PUBLIC_BROWSER_DOWNLOAD_DESTINATION_OBSERVER_H_
+#define CONTENT_PUBLIC_BROWSER_DOWNLOAD_DESTINATION_OBSERVER_H_
+
+#include <string>
+
+#include "content/public/browser/download_interrupt_reasons.h"
+
+namespace content {
+
+// Class that receives asynchronous events from a DownloadDestination about
+// downloading progress and completion.  These should report status when the
+// data arrives at its final location; i.e. DestinationUpdate should be
+// called after the destination is finished with whatever operation it
+// is doing on the data described by |bytes_so_far| and DestinationCompleted
+// should only be called once that is true for all data.
+//
+// All methods are invoked on the UI thread.
+//
+// Note that this interface does not deal with cross-thread lifetime issues.
+class DownloadDestinationObserver {
+ public:
+  virtual void DestinationUpdate(int64 bytes_so_far,
+                                 int64 bytes_per_sec,
+                                 const std::string& hash_state) = 0;
+
+  virtual void DestinationError(DownloadInterruptReason reason) = 0;
+
+  virtual void DestinationCompleted(const std::string& final_hash) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_DESTINATION_OBSERVER_H_