Shift "commit point" for when a download will no longer accept cancels.

content/browser/download/download_file_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.
 
 #include "content/browser/download/download_file_impl.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/file_util.h"
@@ skipping 42 matching lines @@
           weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
           power_save_blocker_(power_save_blocker.Pass()) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK(download_manager.get());
 }
 
 DownloadFileImpl::~DownloadFileImpl() {
 }
 
 content::DownloadInterruptReason DownloadFileImpl::Initialize() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
   update_timer_.reset(new base::RepeatingTimer<DownloadFileImpl>());
-  net::Error result = file_.Initialize(default_download_directory_);
-  if (result != net::OK) {
+  net::Error net_result = file_.Initialize(default_download_directory_);
+  if (net_result != net::OK) {
     return content::ConvertNetErrorToInterruptReason(
-        result, content::DOWNLOAD_INTERRUPT_FROM_DISK);
+        net_result, content::DOWNLOAD_INTERRUPT_FROM_DISK);
   }
 
   stream_reader_->RegisterCallback(
       base::Bind(&DownloadFileImpl::StreamActive, weak_factory_.GetWeakPtr()));
 
   download_start_ = base::TimeTicks::Now();
+
   // Initial pull from the straw.
   StreamActive();
 
   return content::DOWNLOAD_INTERRUPT_REASON_NONE;
 }
 
 content::DownloadInterruptReason DownloadFileImpl::AppendDataToFile(
     const char* data, size_t data_len) {
   if (!update_timer_->IsRunning()) {
     update_timer_->Start(FROM_HERE,
@@ skipping 35 matching lines @@
             rename_error,
             content::DOWNLOAD_INTERRUPT_FROM_DISK);
     new_path.clear();
   }
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(callback, reason, new_path));
 }
 
-void DownloadFileImpl::Detach() {
+void DownloadFileImpl::Detach(base::Closure callback) {
+  // Doing the annotation here leaves a small window during
+  // which the file has the final name but hasn't been marked with the
+  // Mark Of The Web.  However, it allows anti-virus scanners on Windows
+  // to actually see the data (http://crbug.com/127999), and the Window
+  // is pretty small (round trip to the UI thread).
+  AnnotateWithSourceInformation();
+
   file_.Detach();
+
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, callback);

[benjhayden, 2012/09/19 15:44:35]

Seems like there should be a less magical way to do this. Why not
PostTaskAndReply?

[Randy Smith (Not in Mondays), 2012/09/19 20:46:39]

Because I wanted to be able to write a test to delay the callback under test
control, and I couldn't see a way to do that with PostTaskAndReply.

 }
 
 void DownloadFileImpl::Cancel() {
   file_.Cancel();
 }
 
 void DownloadFileImpl::AnnotateWithSourceInformation() {
   bound_net_log_.BeginEvent(net::NetLog::TYPE_DOWNLOAD_FILE_ANNOTATED);
   file_.AnnotateWithSourceInformation();
   bound_net_log_.EndEvent(net::NetLog::TYPE_DOWNLOAD_FILE_ANNOTATED);
@@ skipping 154 matching lines @@
   }
 }
 
 void DownloadFileImpl::SendUpdate() {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&DownloadManager::UpdateDownload,
                  download_manager_, id_.local(),
                  BytesSoFar(), CurrentSpeed(), GetHashState()));
 }