[downloads] Move platform specific code out of DownloadTargetDeterminer.

chrome/browser/download/download_confirmation_result.h

+// Copyright 2016 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.
+
+#ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_CONFIRMATION_RESULT_H_
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_CONFIRMATION_RESULT_H_
+
+enum class DownloadConfirmationResult {
+  CONFIRMED,                     // The user confirmed the path.
+  CANCELED,                      // The user cancelled.
+  CONTINUE_WITHOUT_CONFIRMATION  // User was not prompted, but continue with
+                                 // current path.
+};
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_CONFIRMATION_RESULT_H_