Support restricting browsing data removal for downloads by origin.

content/public/browser/download_manager.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.
 //
 // The DownloadManager object manages the process of downloading, including
 // updates to the history system and providing the information for displaying
 // the downloads view in the Destinations tab. There is one DownloadManager per
 // active browser context in Chrome.
 //
 // Download observers:
@@ skipping 26 matching lines @@
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/time/time.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_url_parameters.h"
 #include "net/base/net_errors.h"
 #include "net/log/net_log.h"
 
 class GURL;
 
+namespace url {
+class Origin;
+}
+
 namespace content {
 
 class BrowserContext;
 class ByteStreamReader;
 class DownloadManagerDelegate;
 class DownloadQuery;
 class DownloadRequestHandle;
 struct DownloadCreateInfo;
 
 // Browser's download manager: manages all downloads and destination view.
@@ skipping 46 matching lines @@
 
   // Called by a download source (Currently DownloadResourceHandler)
   // to initiate the non-source portions of a download.
   // Returns the id assigned to the download.  If the DownloadCreateInfo
   // specifies an id, that id will be used.
   virtual void StartDownload(
       scoped_ptr<DownloadCreateInfo> info,
       scoped_ptr<ByteStreamReader> stream,
       const DownloadUrlParameters::OnStartedCallback& on_started) = 0;
 
-  // Remove downloads after remove_begin (inclusive) and before remove_end
-  // (exclusive). You may pass in null Time values to do an unbounded delete
-  // in either direction.
-  virtual int RemoveDownloadsBetween(base::Time remove_begin,
+  // Remove downloads which are same-origin with the given origin, are after
+  // remove_begin (inclusive), and before remove_end (exclusive). You may pass
+  // in null Time values to do an unbounded delete in either direction. A
+  // unique origin causes all origins to be removed.

[Randy Smith (Not in Mondays), 2015/08/03 19:09:30]

I'm uncomfortable with using unique origins to indicate "all origins".  Could
you instead add a separate interface (maybe |RemoveDownloadByOrigin|) that just
removes origins that match the passed origin without the extra semantics for
unique origins?

[Timo Reimann, 2015/08/03 20:09:32]

Sounds legitimate; especially since mkwst raised similar concerns already.

Internally, I guess we'd want |RemoveDownloadsBetween| and
|RemoveDownloadsByOrigin| to be based on the same implementation with some means
to indicate absence/presence of an origin? If so, I suppose a simple pointer
(with NULL being absence and non-NULL being presence) could fit the purpose
unless we want to have something more sophisticated.

+  virtual int RemoveDownloadsBetween(const url::Origin& origin_to_clear,
+                                     base::Time remove_begin,
                                      base::Time remove_end) = 0;
 
   // Remove downloads will delete all downloads that have a timestamp that is
   // the same or more recent than |remove_begin|. The number of downloads
   // deleted is returned back to the caller.
   virtual int RemoveDownloads(base::Time remove_begin) = 0;
 
   // Remove all downloads will delete all downloads. The number of downloads
   // deleted is returned back to the caller.
   virtual int RemoveAllDownloads() = 0;
@@ skipping 47 matching lines @@
   virtual void CheckForHistoryFilesRemoval() = 0;
 
   // Get the download item for |id| if present, no matter what type of download
   // it is or state it's in.
   virtual DownloadItem* GetDownload(uint32 id) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_MANAGER_H_