Modified cancel and interrupt processing to avoid race with history.

chrome/browser/download/download_history.cc

 // 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.
 
 #include "chrome/browser/download/download_history.h"
 
 #include "base/logging.h"
 #include "chrome/browser/history/download_history_info.h"
 #include "chrome/browser/history/history_marshaling.h"
 #include "chrome/browser/download/download_item.h"
@@ skipping 102 matching lines @@
                                          const FilePath& new_path) {
   // No update necessary if the download was initiated while in incognito mode.
   if (download_item->db_handle() <= kUninitializedHandle)
     return;
 
   HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
   if (hs)
     hs->UpdateDownloadPath(new_path, download_item->db_handle());
 }
 
-void DownloadHistory::RemoveEntry(DownloadItem* download_item) {
+void DownloadHistory::RemoveEntry(int64 db_handle) {
   // No update necessary if the download was initiated while in incognito mode.
-  if (download_item->db_handle() <= kUninitializedHandle)
+  if (db_handle <= kUninitializedHandle)
     return;
 
   HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
   if (hs)
-    hs->RemoveDownload(download_item->db_handle());
+    hs->RemoveDownload(db_handle);
 }
 
 void DownloadHistory::RemoveEntriesBetween(const base::Time remove_begin,
                                            const base::Time remove_end) {
   HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
   if (hs)
     hs->RemoveDownloadsBetween(remove_begin, remove_end);
 }
 
 int64 DownloadHistory::GetNextFakeDbHandle() {
   return next_fake_db_handle_--;
 }
 
+// static
+bool DownloadHistory::IsFakeHandle(int64 db_handle) {
+  return db_handle <= 0;
+}
+
 void DownloadHistory::OnGotVisitCountToHost(HistoryService::Handle handle,
                                             bool found_visits,
                                             int count,
                                             base::Time first_visit) {
   VisitedBeforeRequestsMap::iterator request =
       visited_before_requests_.find(handle);
   DCHECK(request != visited_before_requests_.end());
   int32 download_id = request->second.first;
   VisitedBeforeDoneCallback* callback = request->second.second;
   visited_before_requests_.erase(request);
   callback->Run(download_id, found_visits && count &&
       (first_visit.LocalMidnight() < base::Time::Now().LocalMidnight()));
   delete callback;
 }