Added DownloadProcessHandle class.

chrome/browser/download/download_process_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_PROCESS_HANDLE_H_
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_PROCESS_HANDLE_H_
+#pragma once
+
+#include <string>
+
+class DownloadManager;
+class ResourceDispatcherHost;
+class TabContents;
+
+// Identifiers associated with the download by related subsystems.
+// This class needs to be copyable, but has non-trivial methods.

[Paweł Hajdan Jr., 2011/05/05 20:13:51]

nit: Just remove the part about non-trivial methods, no need to "justify" such
things in comments.

[ahendrickson, 2011/05/06 16:16:50]

Done.

+class DownloadProcessHandle {
+ public:
+  DownloadProcessHandle();
+  DownloadProcessHandle(int child_id, int render_view_id, int request_id);
+
+  void CancelDownload(ResourceDispatcherHost* rdh);
+  TabContents* GetTabContents();
+  DownloadManager* GetDownloadManager();
+
+  int child_id() const { return child_id_; }
+  int render_view_id() const { return render_view_id_; }
+  int request_id() const { return request_id_; }
+
+ private:
+  // The ID of the child process that started the download.
+  int child_id_;

[Paweł Hajdan Jr., 2011/05/05 20:13:51]

Could you make all member variables const?

[ahendrickson, 2011/05/06 16:16:50]

That would prevent the class from being copyable.

Having all the members private, and not having mutators (other than the
assignment operator) achieves what we want.

[Paweł Hajdan Jr., 2011/05/06 18:04:42]

To be precise, I think it would prevent it from being _assignable_. Okay, it's
fine as-is.

+
+  // 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_PROCESS_HANDLE_H_