Change DownloadProcessHandle to be more of an encapsulated class.

chrome/browser/download/download_request_handle.h

+// Copyright (c) 2011 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_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_
+#pragma once
+
+#include <string>
+
+class DownloadManager;
+class ResourceDispatcherHost;
+class TabContents;
+
+// A handle used by the download system for operations on the URLRequest
+// or objects conditional on it (e.g. TabContents).
+// This class needs to be copyable, so we can pass it across threads and not
+// worry about lifetime or const-ness.
+class DownloadRequestHandle {
+ public:
+

[Paweł Hajdan Jr., 2011/06/08 09:36:58]

nit: Remove empty line.

[Randy Smith (Not in Mondays), 2011/06/09 13:17:43]

Done.

+  // Create a null DownloadRequestHandle; getters return null, and no
+  // actions are allowed.
+  DownloadRequestHandle();
+
+  // Note that rdh is required to be non-null.

[Paweł Hajdan Jr., 2011/06/08 09:36:58]

nit: |rdh|

[Randy Smith (Not in Mondays), 2011/06/09 13:17:43]

Done.

+  DownloadRequestHandle(ResourceDispatcherHost* rdh,
+                        int child_id,
+                        int render_view_id,
+                        int request_id);
+
+  // These functions must be called on the UI thread.
+  TabContents* GetTabContents() const;
+  DownloadManager* GetDownloadManager() const;
+
+  // Pause or resume the matching URL request.
+  void PauseRequest();
+  void ResumeRequest();
+
+  // Cancel the request
+  void CancelRequest();
+
+  std::string DebugString() const;
+
+ private:
+  friend class DownloadFileTest;
+
+  // Some unit tests don't setup the ResourceDispatcherHost; for these
+  // tests we allow the creation of a no-op DownloadRequestHandle which
+  // returns null and no-ops the handle actions.
+  static DownloadRequestHandle GetNopDownloadRequestHandle();
+
+  // Helper functions for distinguishing special DownloadRequestHandles
+  bool IsNull() const;
+  bool IsNop() const;
+
+  // The resource dispatcher host.
+  ResourceDispatcherHost* rdh_;
+
+  // The ID of the child process that started the download.
+  int child_id_;
+
+  // The ID of the render view that started the download.
+  int render_view_id_;
+
+  // The ID associated with the request used for the download.
+  int request_id_;
+};
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_