Implement DownloadFile::Rename() for posix. Downloads work on linux!

chrome/browser/download/download_file.cc

 // Copyright (c) 2006-2008 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_file.h"
 
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/scoped_ptr.h"
 #include "base/string_util.h"
@@ skipping 72 matching lines @@
   return false;
 }
 
 void DownloadFile::Cancel() {
   Close();
   file_util::Delete(full_path_, false);
 }
 
 // The UI has provided us with our finalized name.
 bool DownloadFile::Rename(const FilePath& new_path) {
-#if defined(OS_WIN)
   Close();
 
+#if defined(OS_WIN)
   // We cannot rename because rename will keep the same security descriptor
   // on the destination file. We want to recreate the security descriptor
   // with the security that makes sense in the new path.
-  if (!file_util::RenameFileAndResetSecurityDescriptor(full_path_, new_path)) {
+  if (!file_util::RenameFileAndResetSecurityDescriptor(full_path_, new_path))
     return false;
-  }
-
+  // TODO(estade): is this necessary?
   file_util::Delete(full_path_, false);
+#elif defined(OS_POSIX)
+  // TODO(estade): Move() falls back to copying and deleting when a simple
+  // rename fails. Copying sucks for large downloads. crbug.com/8737
+  if (!file_util::Move(full_path_, new_path))
+      return false;
+#endif
 
   full_path_ = new_path;
   path_renamed_ = true;
 
   // We don't need to re-open the file if we're done (finished or canceled).
   if (!in_progress_)
     return true;
 
   if (!Open("a+b"))
     return false;
   return true;
-#elif defined(OS_POSIX)
-  // TODO(port): Port this function to posix (we need file_util::Rename()).
-  NOTIMPLEMENTED();
-  return false;
-#endif
 }
 
 void DownloadFile::Close() {
   if (file_) {
     file_util::CloseFile(file_);
     file_ = NULL;
   }
 }
 
 bool DownloadFile::Open(const char* open_mode) {
@@ skipping 465 matching lines @@
     ui_loop_->PostTask(FROM_HERE, NewRunnableMethod(
         this, &DownloadFileManager::StopUpdateTimer));
 }
 
 // static
 void DownloadFileManager::DeleteFile(const FilePath& path) {
   // Make sure we only delete files.
   if (!file_util::DirectoryExists(path))
     file_util::Delete(path, false);
 }