[Downloads] Allow acquiring dangerous download file.

content/browser/download/download_item_impl.cc

 // 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.
 
 // File method ordering: Methods in this file are in the same order as
 // in download_item_impl.h, with the following exception: The public
 // interface Start is placed in chronological order with the other
 // (private) routines that together define a DownloadItem's state
 // transitions as the download progresses.  See "Download progression
 // cascade" later in this file.
@@ skipping 50 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   // Make sure we only delete files.
   if (!file_util::DirectoryExists(path))
     file_util::Delete(path, false);
 }
 
 // Wrapper around DownloadFile::Detach and DownloadFile::Cancel that
 // takes ownership of the DownloadFile and hence implicitly destroys it
 // at the end of the function.
-static void DownloadFileDetach(scoped_ptr<DownloadFile> download_file) {
+static base::FilePath DownloadFileDetach(
+    scoped_ptr<DownloadFile> download_file) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  base::FilePath full_path = download_file->FullPath();
   download_file->Detach();
+  return full_path;
 }
 
 static void DownloadFileCancel(scoped_ptr<DownloadFile> download_file) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   download_file->Cancel();
 }
 
 bool IsDownloadResumptionEnabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableDownloadResumption);
@@ skipping 311 matching lines @@
   // (In the latter case the DownloadFile object will delete it on cancel.)
   if (!current_path_.empty() && download_file_.get() == NULL) {
     BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
                             base::Bind(&DeleteDownloadedFile, current_path_));
     current_path_.clear();
   }
   Remove();
   // We have now been deleted.
 }
 
+void DownloadItemImpl::AcquireFileAndDeleteDownload(
+    const AcquireFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (download_file_) {
+    BrowserThread::PostTaskAndReplyWithResult(
+        BrowserThread::FILE,
+        FROM_HERE,
+        base::Bind(&DownloadFileDetach, base::Passed(&download_file_)),
+        callback);
+  } else {
+    callback.Run(current_path_);

[Randy Smith (Not in Mondays), 2013/05/23 13:56:43]

Under what circumstances will we take this path?  It seems like it would only
happen if downloads were complete; do we want to support that case?

[asanka, 2013/05/24 01:17:11]

It could also be interrupted.

+  }
+  current_path_.clear();
+  Delete(DELETE_DUE_TO_USER_DISCARD);
+}
+
 void DownloadItemImpl::Remove() {
   VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // Remove the intermediate file if we are removing an interrupted download.
   // Continuable interruptions leave the intermediate file around. However, the
   // intermediate file will be unusable if the download item is removed.
   if (!current_path_.empty() && IsInterrupted() && !download_file_.get()) {
     BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
                             base::Bind(&DeleteDownloadedFile, current_path_));
@@ skipping 976 matching lines @@
 
   if (destroy_file) {
     BrowserThread::PostTask(
         BrowserThread::FILE, FROM_HERE,
         // Will be deleted at end of task execution.
         base::Bind(&DownloadFileCancel, base::Passed(&download_file_)));
     // Avoid attempting to reuse the intermediate file by clearing out
     // current_path_.
     current_path_.clear();
   } else {
-    BrowserThread::PostTask(
-        BrowserThread::FILE, FROM_HERE,
-        // Will be deleted at end of task execution.
-        base::Bind(&DownloadFileDetach, base::Passed(&download_file_)));
+    BrowserThread::PostTask(BrowserThread::FILE,
+                            FROM_HERE,
+                            // Will be deleted at end of task execution.

[Randy Smith (Not in Mondays), 2013/05/23 13:56:43]

Could you move this comment down a line to make clear what it's referring to?

[asanka, 2013/05/24 01:17:11]

Done.

+                            base::Bind(base::IgnoreResult(&DownloadFileDetach),
+                                       base::Passed(&download_file_)));
   }
   // Don't accept any more messages from the DownloadFile, and null
   // out any previous "all data received".  This also breaks links to
   // other entities we've given out weak pointers to.
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 bool DownloadItemImpl::IsDownloadReadyForCompletion(
     const base::Closure& state_change_notification) {
   // If we don't have all the data, the download is not ready for
@@ skipping 263 matching lines @@
     case RESUME_MODE_USER_CONTINUE:
       return "USER_CONTINUE";
     case RESUME_MODE_USER_RESTART:
       return "USER_RESTART";
   }
   NOTREACHED() << "Unknown resume mode " << mode;
   return "unknown";
 }
 
 }  // namespace content